diff --git a/.gitignore b/.gitignore
index 70935fdb..c737ee92 100644
--- a/.gitignore
+++ b/.gitignore
@@ -7,5 +7,8 @@ lombok.config
 .vscode/
 .cursor
 .github/SKILL.md
+.github/copilot-instructions.md
 swagger-spec.json
-swagger.*
\ No newline at end of file
+swagger.*
+.claude/
+CLAUDE.md
diff --git a/src/main/java/com/checkout/GsonSerializer.java b/src/main/java/com/checkout/GsonSerializer.java
index ab47de5d..f40577af 100644
--- a/src/main/java/com/checkout/GsonSerializer.java
+++ b/src/main/java/com/checkout/GsonSerializer.java
@@ -161,7 +161,8 @@ public final class GsonSerializer implements Serializer {
             // Payments - source
             .registerTypeAdapterFactory(RuntimeTypeAdapterFactory.of(com.checkout.payments.response.source.ResponseSource.class, CheckoutUtils.TYPE, true, com.checkout.payments.response.source.AlternativePaymentSourceResponse.class)
                     .registerSubtype(com.checkout.payments.response.source.CardResponseSource.class, identifier(PaymentSourceType.CARD))
-                    .registerSubtype(com.checkout.payments.response.source.CurrencyAccountResponseSource.class, identifier(PaymentSourceType.CURRENCY_ACCOUNT)))
+                    .registerSubtype(com.checkout.payments.response.source.CurrencyAccountResponseSource.class, identifier(PaymentSourceType.CURRENCY_ACCOUNT))
+                    .registerSubtype(com.checkout.payments.response.source.PayPalResponseSource.class, identifier(PaymentSourceType.PAYPAL)))
             // Payment Contexts
             .registerTypeAdapterFactory(RuntimeTypeAdapterFactory.of(com.checkout.payments.response.source.contexts.ResponseSource.class, CheckoutUtils.TYPE, true, com.checkout.payments.response.source.contexts.AlternativePaymentSourceResponse.class)
                     .registerSubtype(com.checkout.payments.response.source.contexts.PaymentContextsPayPalResponseSource.class, identifier(PaymentSourceType.PAYPAL))
@@ -187,7 +188,9 @@ public final class GsonSerializer implements Serializer {
                     .registerSubtype(com.checkout.instruments.get.GetSepaInstrumentResponse.class, identifier(InstrumentType.SEPA)))
             .registerTypeAdapterFactory(RuntimeTypeAdapterFactory.of(com.checkout.instruments.update.UpdateInstrumentResponse.class, CheckoutUtils.TYPE)
                     .registerSubtype(com.checkout.instruments.update.UpdateInstrumentBankAccountResponse.class, identifier(InstrumentType.BANK_ACCOUNT))
-                    .registerSubtype(com.checkout.instruments.update.UpdateInstrumentCardResponse.class, identifier(InstrumentType.CARD)))
+                    .registerSubtype(com.checkout.instruments.update.UpdateInstrumentCardResponse.class, identifier(InstrumentType.CARD))
+                    .registerSubtype(com.checkout.instruments.update.UpdateInstrumentSepaResponse.class, identifier(InstrumentType.SEPA))
+                    .registerSubtype(com.checkout.instruments.update.UpdateInstrumentAchResponse.class, identifier(InstrumentType.ACH)))
             // Workflows CS2
             .registerTypeAdapterFactory(RuntimeTypeAdapterFactory.of(com.checkout.workflows.actions.response.WorkflowActionResponse.class, CheckoutUtils.TYPE)
                     .registerSubtype(com.checkout.workflows.actions.response.WebhookWorkflowActionResponse.class, identifier(WorkflowActionType.WEBHOOK)))
diff --git a/src/main/java/com/checkout/accounts/UpdatePaymentInstrumentRequest.java b/src/main/java/com/checkout/accounts/UpdatePaymentInstrumentRequest.java
index 29aba57b..40fe2d68 100644
--- a/src/main/java/com/checkout/accounts/UpdatePaymentInstrumentRequest.java
+++ b/src/main/java/com/checkout/accounts/UpdatePaymentInstrumentRequest.java
@@ -8,10 +8,22 @@
 @Data
 @ToString(callSuper = true)
 @EqualsAndHashCode(callSuper = true)
-public final class UpdatePaymentInstrumentRequest extends Headers{
+public final class UpdatePaymentInstrumentRequest extends Headers {
 
+    /**
+     * A reference that you can use to identify the payment instrument.
+     * [Optional]
+     */
     private String label;
 
+    /**
+     * Whether the payment instrument should be set as the default payout destination.
+     * For ad-hoc payouts the instrument is specified explicitly; for scheduled payouts the first instrument
+     * created for a currency is used. To change the instrument for a payout schedule, update the schedule.
+     * [Optional]
+     * @deprecated Update the payout schedule instead.
+     */
+    @Deprecated
     @SerializedName("default")
     private Boolean defaultDestination;
 }
diff --git a/src/main/java/com/checkout/common/InstrumentType.java b/src/main/java/com/checkout/common/InstrumentType.java
index 73d8e7b4..e6b606e6 100644
--- a/src/main/java/com/checkout/common/InstrumentType.java
+++ b/src/main/java/com/checkout/common/InstrumentType.java
@@ -17,6 +17,9 @@ public enum InstrumentType {
     CARD_TOKEN,
 
     @SerializedName("sepa")
-    SEPA
+    SEPA,
+
+    @SerializedName("ach")
+    ACH
 
 }
diff --git a/src/main/java/com/checkout/common/Link.java b/src/main/java/com/checkout/common/Link.java
index 92c90c96..059f59b6 100644
--- a/src/main/java/com/checkout/common/Link.java
+++ b/src/main/java/com/checkout/common/Link.java
@@ -5,10 +5,34 @@
 @Data
 public final class Link {
 
+    /**
+     * The link URL.
+     * [Optional]
+     */
     private final String href;
 
+    /**
+     * The link title.
+     * [Optional]
+     */
     private final String title;
 
+    /**
+     * The link relation type.
+     * [Optional]
+     */
     private final String link;
 
-}
\ No newline at end of file
+    /**
+     * Mobile deep-link redirect URLs for Android and iOS redirect payments.
+     * [Optional]
+     */
+    private MobileRedirectLink mobile;
+
+    /**
+     * QR code data for redirect payments.
+     * [Optional]
+     */
+    private QrCode qrCode;
+
+}
diff --git a/src/main/java/com/checkout/common/MobileRedirectLink.java b/src/main/java/com/checkout/common/MobileRedirectLink.java
new file mode 100644
index 00000000..1b2911c0
--- /dev/null
+++ b/src/main/java/com/checkout/common/MobileRedirectLink.java
@@ -0,0 +1,33 @@
+package com.checkout.common;
+
+import lombok.Data;
+
+/**
+ * Mobile deep-link redirect URLs returned in 202 payment response _links.redirect.
+ */
+@Data
+public final class MobileRedirectLink {
+
+    /**
+     * The Android deep-link redirect URL.
+     * [Optional]
+     */
+    private PlatformLink android;
+
+    /**
+     * The iOS deep-link redirect URL.
+     * [Optional]
+     */
+    private PlatformLink ios;
+
+    @Data
+    public static final class PlatformLink {
+
+        /**
+         * The deep-link URL.
+         * [Optional]
+         */
+        private String href;
+    }
+
+}
diff --git a/src/main/java/com/checkout/common/Product.java b/src/main/java/com/checkout/common/Product.java
index a34be0b1..2f9fcc20 100644
--- a/src/main/java/com/checkout/common/Product.java
+++ b/src/main/java/com/checkout/common/Product.java
@@ -3,17 +3,41 @@
 import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Data;
+import lombok.NoArgsConstructor;
 
 @Data
 @Builder
+@NoArgsConstructor
 @AllArgsConstructor
 public final class Product {
 
+    /**
+     * The name of the product.
+     * [Optional]
+     */
     private String name;
 
+    /**
+     * The quantity of the product.
+     * [Optional]
+     */
     private Long quantity;
 
+    /**
+     * The price of the product in minor currency units.
+     * [Optional]
+     */
     private Long price;
 
+    /**
+     * A reference you can use to identify the product.
+     * [Optional]
+     */
     private String reference;
+
+    /**
+     * The URL of the product.
+     * [Optional]
+     */
+    private String url;
 }
diff --git a/src/main/java/com/checkout/common/QrCode.java b/src/main/java/com/checkout/common/QrCode.java
new file mode 100644
index 00000000..4039bf51
--- /dev/null
+++ b/src/main/java/com/checkout/common/QrCode.java
@@ -0,0 +1,23 @@
+package com.checkout.common;
+
+import lombok.Data;
+
+/**
+ * QR code data returned for payment methods that require a QR code scan, in 202 responses.
+ */
+@Data
+public final class QrCode {
+
+    /**
+     * The QR code as a base64-encoded image.
+     * [Optional]
+     */
+    private String image;
+
+    /**
+     * The raw text encoded in the QR code.
+     * [Optional]
+     */
+    private String text;
+
+}
diff --git a/src/main/java/com/checkout/disputes/CompellingEvidence.java b/src/main/java/com/checkout/disputes/CompellingEvidence.java
index 3a9cbf81..0ad4d24a 100644
--- a/src/main/java/com/checkout/disputes/CompellingEvidence.java
+++ b/src/main/java/com/checkout/disputes/CompellingEvidence.java
@@ -1,37 +1,75 @@
 package com.checkout.disputes;
 
-import com.google.gson.annotations.SerializedName;
-
 import java.time.Instant;
 import java.util.List;
 
 public final class CompellingEvidence {
 
-    @SerializedName("merchandise_or_service")
+    /**
+     * Whether the evidence concerns merchandise or services.
+     * [Required]
+     * Enum: "Merchandise" "Services"
+     */
     private String merchandiseOrService;
 
-    @SerializedName("merchandise_or_service_desc")
+    /**
+     * A description of the merchandise or service provided.
+     * [Required]
+     * min 1 character, max 5000 characters
+     */
     private String merchandiseOrServiceDesc;
 
-    @SerializedName("merchandise_or_service_provided_date")
+    /**
+     * The date the merchandise or service was provided to the customer.
+     * [Required]
+     * Format: date-time (RFC 3339)
+     */
     private Instant merchandiseOrServiceProvidedDate;
 
-    @SerializedName("shipping_delivery_status")
+    /**
+     * The shipping or delivery status of the merchandise.
+     * [Optional]
+     */
     private ShippingDeliveryStatusType shippingDeliveryStatus;
 
-    @SerializedName("tracking_information")
+    /**
+     * The tracking number for the shipment.
+     * [Optional]
+     * max 50 characters
+     */
     private TrackingInformationType trackingInformation;
 
-    @SerializedName("user_id")
+    /**
+     * The customer's account or login identifier.
+     * [Optional]
+     * max 50 characters
+     */
     private String userId;
 
-    @SerializedName("ip_address")
+    /**
+     * The IP address used for the transaction (IPv4 or IPv6).
+     * [Optional]
+     */
     private String ipAddress;
 
-    @SerializedName("shipping_address")
+    /**
+     * The device identifier used for the transaction.
+     * [Optional]
+     * min 15 characters, max 64 characters
+     */
+    private String deviceId;
+
+    /**
+     * The shipping address used for the transaction.
+     * [Optional]
+     */
     private ShippingAddress shippingAddress;
 
-    @SerializedName("historical_transactions")
+    /**
+     * Prior undisputed transactions between the merchant and the same customer.
+     * At least 2 items required.
+     * [Required]
+     */
     private List<HistoricalTransactions> historicalTransactions;
 
 }
diff --git a/src/main/java/com/checkout/disputes/Dispute.java b/src/main/java/com/checkout/disputes/Dispute.java
index df315f29..48f88b79 100644
--- a/src/main/java/com/checkout/disputes/Dispute.java
+++ b/src/main/java/com/checkout/disputes/Dispute.java
@@ -2,7 +2,6 @@
 
 import com.checkout.common.Currency;
 import com.checkout.common.Resource;
-import com.google.gson.annotations.SerializedName;
 import lombok.Builder;
 import lombok.Data;
 import lombok.EqualsAndHashCode;
@@ -16,54 +15,137 @@
 @EqualsAndHashCode(callSuper = false)
 public final class Dispute extends Resource {
 
+    /**
+     * The dispute identifier.
+     * [Optional]
+     * ^(dsp)_(\w{22,26})$
+     */
     private String id;
 
+    /**
+     * The reason for the dispute.
+     * [Optional]
+     */
     private DisputeCategory category;
 
+    /**
+     * The current status of the dispute.
+     * [Optional]
+     */
     private DisputeStatus status;
 
+    /**
+     * The disputed amount in the processing currency.
+     * [Optional]
+     */
     private Long amount;
 
+    /**
+     * The processing currency.
+     * [Optional]
+     */
     private Currency currency;
 
-    @SerializedName("reason_code")
+    /**
+     * The card scheme reason code for the dispute.
+     * [Optional]
+     */
     private String reasonCode;
 
-    @SerializedName("payment_id")
+    /**
+     * The payment identifier.
+     * [Optional]
+     */
     private String paymentId;
 
-    @SerializedName("payment_action_id")
+    /**
+     * The payment action identifier.
+     * [Optional]
+     */
     private String paymentActionId;
 
-    @SerializedName("payment_reference")
+    /**
+     * The payment reference or order ID.
+     * [Optional]
+     */
     private String paymentReference;
 
-    @SerializedName("payment_arn")
+    /**
+     * The acquirer reference number for the payment.
+     * [Optional]
+     */
     private String paymentArn;
 
-    @SerializedName("payment_method")
+    /**
+     * The payment method or card scheme.
+     * [Optional]
+     */
     private String paymentMethod;
 
-    @SerializedName("evidence_required_by")
+    /**
+     * The deadline by which evidence must be submitted.
+     * [Optional]
+     * Format: date-time (RFC 3339)
+     */
     private Instant evidenceRequiredBy;
 
-    @SerializedName("received_on")
+    /**
+     * The date and time the dispute was issued.
+     * [Optional]
+     * Format: date-time (RFC 3339)
+     */
     private Instant receivedOn;
 
-    @SerializedName("last_update")
+    /**
+     * The date and time of the last update to the dispute.
+     * [Optional]
+     * Format: date-time (RFC 3339)
+     */
     private Instant lastUpdate;
 
     /**
-     * Not available on Previous
+     * The reason the dispute was automatically resolved.
+     * [Optional]
+     * Enum: "rapid_dispute_resolution" "negative_amount" "already_refunded"
      */
+    private DisputeResolvedReason resolvedReason;
 
-    @SerializedName("entity_id")
+    /**
+     * Whether the dispute is eligible for Visa Compelling Evidence 3.0.
+     * [Optional]
+     */
+    private Boolean isCeCandidate;
+
+    // Not available on Previous API
+
+    /**
+     * The client entity linked to this dispute.
+     * [Optional]
+     */
     private String entityId;
 
-    @SerializedName("sub_entity_id")
+    /**
+     * The sub-entity linked to this dispute.
+     * [Optional]
+     */
     private String subEntityId;
 
-    @SerializedName("payment_mcc")
+    /**
+     * The processing channel linked to this dispute.
+     * [Optional]
+     */
+    private String processingChannel;
+
+    /**
+     * The business segment identifier.
+     * [Optional]
+     */
+    private String segmentId;
+
+    /**
+     * The merchant category code for the payment.
+     * [Optional]
+     */
     private String paymentMcc;
 
 }
diff --git a/src/main/java/com/checkout/disputes/DisputeRelevantEvidence.java b/src/main/java/com/checkout/disputes/DisputeRelevantEvidence.java
index 067cd558..43a85bbe 100644
--- a/src/main/java/com/checkout/disputes/DisputeRelevantEvidence.java
+++ b/src/main/java/com/checkout/disputes/DisputeRelevantEvidence.java
@@ -25,6 +25,12 @@ public enum DisputeRelevantEvidence {
     @SerializedName("additional_evidence")
     ADDITIONAL_EVIDENCE,
 
+    @SerializedName("proof_of_delivery_or_service_date")
+    PROOF_OF_DELIVERY_OR_SERVICE_DATE,
+
+    @SerializedName("compelling_evidence")
+    COMPELLING_EVIDENCE,
+
     @SerializedName("arbitration_no_review")
     ARBITRATION_NO_REVIEW,
 
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/flow/entities/ApplePayConfiguration.java b/src/main/java/com/checkout/handlepaymentsandpayouts/flow/entities/ApplePayConfiguration.java
index 3063fe1d..f4c2af1f 100644
--- a/src/main/java/com/checkout/handlepaymentsandpayouts/flow/entities/ApplePayConfiguration.java
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/flow/entities/ApplePayConfiguration.java
@@ -18,7 +18,8 @@ public final class ApplePayConfiguration extends PaymentMethodConfigurationBase
 
     /**
      * The type of the Apple Pay payment total line item. Default: "final"
+     * [Optional]
      */
     @Builder.Default
     private TotalType totalType = TotalType.FINAL;
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/flow/entities/Customer.java b/src/main/java/com/checkout/handlepaymentsandpayouts/flow/entities/Customer.java
index 20e9337d..b15f3bca 100644
--- a/src/main/java/com/checkout/handlepaymentsandpayouts/flow/entities/Customer.java
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/flow/entities/Customer.java
@@ -1,7 +1,6 @@
 package com.checkout.handlepaymentsandpayouts.flow.entities;
 
 import com.checkout.common.Phone;
-import com.google.gson.annotations.SerializedName;
 import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Data;
@@ -20,31 +19,37 @@ public final class Customer {
 
     /**
      * The customer's email address. Required if source.type is tamara.
+     * [Optional]
      */
     private String email;
 
     /**
      * The customer's name. Required if source.type is tamara.
+     * [Optional]
      */
     private String name;
 
     /**
      * The unique identifier for an existing customer.
+     * [Optional]
      */
     private String id;
 
     /**
      * The customer's phone number. Required if source.type is tamara.
+     * [Optional]
      */
     private Phone phone;
 
     /**
      * The customer's value-added tax (VAT) registration number.
+     * [Optional]
      */
     private String taxNumber;
 
     /**
-     * Summary of the customer's transaction history. Used for risk assessment when source.type is Tamara
+     * Summary of the customer's transaction history. Used for risk assessment when source.type is Tamara.
+     * [Optional]
      */
     private CustomerSummary summary;
 
@@ -59,36 +64,46 @@ public static class CustomerSummary {
 
         /**
          * The date the customer registered.
+         * [Optional]
+         * Format: yyyy-MM-dd
          */
         private LocalDate registrationDate;
 
         /**
          * The date of the customer's first transaction.
+         * [Optional]
+         * Format: yyyy-MM-dd
          */
         private LocalDate firstTransactionDate;
 
         /**
          * The date of the customer's last payment.
+         * [Optional]
+         * Format: yyyy-MM-dd
          */
         private LocalDate lastPaymentDate;
 
         /**
          * The total number of orders made by the customer.
+         * [Optional]
          */
         private Integer totalOrderCount;
 
         /**
          * The amount of the customer's last payment.
+         * [Optional]
          */
         private Double lastPaymentAmount;
 
         /**
          * Specifies whether the customer is a premium customer.
+         * [Optional]
          */
         private Boolean isPremiumCustomer;
 
         /**
          * Specifies whether the customer is a returning customer.
+         * [Optional]
          */
         private Boolean isReturningCustomer;
 
@@ -96,7 +111,8 @@ public static class CustomerSummary {
          * The customer's lifetime value. This is the total monetary amount that the customer has ordered,
          * in their local currency, excluding canceled orders, rejected payments, refunded payments, and Tamara payments.
          * The lifetime value is an indicator of how valuable the relationship with the customer is to your company.
+         * [Optional]
          */
         private Double lifetimeValue;
     }
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/flow/entities/CustomerRetry.java b/src/main/java/com/checkout/handlepaymentsandpayouts/flow/entities/CustomerRetry.java
index 19bae096..bcc2384e 100644
--- a/src/main/java/com/checkout/handlepaymentsandpayouts/flow/entities/CustomerRetry.java
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/flow/entities/CustomerRetry.java
@@ -16,7 +16,8 @@ public final class CustomerRetry {
 
     /**
      * The maximum number of authorization retry attempts, excluding the initial authorization. Default: 5
+     * [Optional]
      */
     @Builder.Default
     private Integer maxAttempts = 5;
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/flow/entities/GooglePayConfiguration.java b/src/main/java/com/checkout/handlepaymentsandpayouts/flow/entities/GooglePayConfiguration.java
index 35f44157..b7b32739 100644
--- a/src/main/java/com/checkout/handlepaymentsandpayouts/flow/entities/GooglePayConfiguration.java
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/flow/entities/GooglePayConfiguration.java
@@ -18,7 +18,8 @@ public final class GooglePayConfiguration extends PaymentMethodConfigurationBase
 
     /**
      * The status of the Google Pay payment total price. Default: "final"
+     * [Optional]
      */
     @Builder.Default
     private TotalPriceStatus totalPriceStatus = TotalPriceStatus.FINAL;
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/flow/entities/PaymentAction.java b/src/main/java/com/checkout/handlepaymentsandpayouts/flow/entities/PaymentAction.java
index f55572d1..e98ff447 100644
--- a/src/main/java/com/checkout/handlepaymentsandpayouts/flow/entities/PaymentAction.java
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/flow/entities/PaymentAction.java
@@ -15,17 +15,20 @@
 public final class PaymentAction {
 
     /**
-     * The type of action required
+     * The type of action required.
+     * [Optional]
      */
     private String type;
 
     /**
-     * A URL the customer should be redirected to for further action (if type requires redirect)
+     * A URL the customer should be redirected to for further action (if type requires redirect).
+     * [Optional]
      */
     private String url;
 
     /**
-     * Additional data needed for the action
+     * Additional data needed for the action.
+     * [Optional]
      */
     private Object data;
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/flow/entities/PaymentMethodConfiguration.java b/src/main/java/com/checkout/handlepaymentsandpayouts/flow/entities/PaymentMethodConfiguration.java
index a606d8e7..cbfed282 100644
--- a/src/main/java/com/checkout/handlepaymentsandpayouts/flow/entities/PaymentMethodConfiguration.java
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/flow/entities/PaymentMethodConfiguration.java
@@ -17,23 +17,27 @@ public final class PaymentMethodConfiguration {
 
     /**
      * Configuration options specific to Apple Pay payments.
+     * [Optional]
      */
     @SerializedName("applepay")
     private ApplePayConfiguration applePay;
 
     /**
      * Configuration options specific to card payments.
+     * [Optional]
      */
     private CardConfiguration card;
 
     /**
      * Configuration options specific to Google Pay payments.
+     * [Optional]
      */
     @SerializedName("googlepay")
     private GooglePayConfiguration googlePay;
 
     /**
      * Configuration options specific to stored card payments.
+     * [Optional]
      */
     private StoredCardConfiguration storedCard;
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/flow/entities/PaymentMethodConfigurationBase.java b/src/main/java/com/checkout/handlepaymentsandpayouts/flow/entities/PaymentMethodConfigurationBase.java
index bcd97556..7585c8f5 100644
--- a/src/main/java/com/checkout/handlepaymentsandpayouts/flow/entities/PaymentMethodConfigurationBase.java
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/flow/entities/PaymentMethodConfigurationBase.java
@@ -16,11 +16,13 @@ public abstract class PaymentMethodConfigurationBase {
 
     /**
      * Specifies whether you intend to store the cardholder's payment details. Default: "disabled"
+     * [Optional]
      */
     private StorePaymentDetailsType storePaymentDetails = StorePaymentDetailsType.DISABLED;
 
     /**
      * The account holder's details.
+     * [Optional]
      */
     private AccountHolder accountHolder;
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/flow/entities/StoredCardConfiguration.java b/src/main/java/com/checkout/handlepaymentsandpayouts/flow/entities/StoredCardConfiguration.java
index 9a0dcd3b..aba2ec92 100644
--- a/src/main/java/com/checkout/handlepaymentsandpayouts/flow/entities/StoredCardConfiguration.java
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/flow/entities/StoredCardConfiguration.java
@@ -18,16 +18,19 @@ public final class StoredCardConfiguration {
 
     /**
      * The unique identifier for an existing customer.
+     * [Optional]
      */
     private String customerId;
 
     /**
      * The unique identifiers for card Instruments.
+     * [Optional]
      */
     private List<String> instrumentIds;
 
     /**
      * The unique identifier for the payment instrument to present to the customer as the default option.
+     * [Optional]
      */
     private String defaultInstrumentId;
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/flow/requests/PaymentSessionBase.java b/src/main/java/com/checkout/handlepaymentsandpayouts/flow/requests/PaymentSessionBase.java
index ef875254..4330cee3 100644
--- a/src/main/java/com/checkout/handlepaymentsandpayouts/flow/requests/PaymentSessionBase.java
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/flow/requests/PaymentSessionBase.java
@@ -25,31 +25,38 @@ public abstract class PaymentSessionBase {
      * The payment amount. Provide a value of 0 to perform a card verification.
      * The amount must be provided in the minor currency unit.
      * For example, provide 10000 for £100.00, or provide 100 for ¥100 (a zero-decimal currency).
+     * [Optional]
+     * min 0
      */
     private Long amount;
-    
+
     /**
      * A reference you can use to identify the payment. For example, an order number.
      * For Amex payments, this must be at most 30 characters.
      * For Benefit payments, the reference must be a unique alphanumeric value.
      * For iDEAL payments, the reference is required and must be an alphanumeric value with a 35-character limit.
+     * [Optional]
      */
     private String reference;
 
     /**
      * The line items in the order.
+     * [Optional]
      */
     private List<ProductRequest> items;
 
     /**
      * Information required for 3D Secure authentication payments.
+     * [Optional]
      */
     @SerializedName("3ds")
     private ThreeDSRequest threeDS;
 
     /**
      * Must be specified for card-not-present (CNP) payments. Default: "Regular"
+     * [Optional]
+     * Enum: "Regular" "Recurring" "MOTO" "Installment" "PayLater" "Unscheduled"
      */
     @Builder.Default
     private PaymentType paymentType = PaymentType.REGULAR;
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/flow/requests/PaymentSessionCompleteRequest.java b/src/main/java/com/checkout/handlepaymentsandpayouts/flow/requests/PaymentSessionCompleteRequest.java
index 78ceac75..4f5c8eec 100644
--- a/src/main/java/com/checkout/handlepaymentsandpayouts/flow/requests/PaymentSessionCompleteRequest.java
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/flow/requests/PaymentSessionCompleteRequest.java
@@ -20,14 +20,16 @@ public final class PaymentSessionCompleteRequest extends PaymentSessionInfo {
 
     /**
      * Creates a translated version of the page in the specified language. Default: "en-GB"
+     * [Optional]
      */
     @Builder.Default
     private LocaleType locale = LocaleType.EN_GB;
 
     /**
-     * A unique token representing the additional customer data captured by Flow, 
+     * A unique token representing the additional customer data captured by Flow,
      * as received from the handleSubmit callback.
      * Do not log or store this value.
+     * [Optional]
      */
     private String sessionData;
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/flow/requests/PaymentSessionCreateRequest.java b/src/main/java/com/checkout/handlepaymentsandpayouts/flow/requests/PaymentSessionCreateRequest.java
index fec9838e..6ddd34ef 100644
--- a/src/main/java/com/checkout/handlepaymentsandpayouts/flow/requests/PaymentSessionCreateRequest.java
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/flow/requests/PaymentSessionCreateRequest.java
@@ -26,38 +26,46 @@ public final class PaymentSessionCreateRequest extends PaymentSessionInfo {
 
     /**
      * Creates a translated version of the page in the specified language. Default: "en-GB"
+     * [Optional]
      */
     @Builder.Default
     private LocaleType locale = LocaleType.EN_GB;
 
     /**
      * A timestamp specifying when the PaymentSession should expire, as an ISO 8601 code.
+     * [Optional]
+     * Format: date-time (ISO 8601)
      */
     private Instant expiresOn;
 
     /**
      * Specifies which payment method options to present to the customer.
+     * [Optional]
      */
     private List<PaymentMethodType> enabledPaymentMethods;
 
     /**
      * Specifies which payment method options to not present to the customer.
+     * [Optional]
      */
     private List<PaymentMethodType> disabledPaymentMethods;
 
     /**
      * Configurations for payment method-specific settings.
+     * [Optional]
      */
     private PaymentMethodConfiguration paymentMethodConfiguration;
 
     /**
      * Configuration for asynchronous retries.
+     * [Optional]
      */
     private CustomerRetry customerRetry;
 
     /**
      * Deprecated - The Customer's IP address. Only IPv4 and IPv6 addresses are accepted.
+     * [Optional]
      */
     @Deprecated
     private String ipAddress;
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/flow/requests/PaymentSessionInfo.java b/src/main/java/com/checkout/handlepaymentsandpayouts/flow/requests/PaymentSessionInfo.java
index 80e543da..fa5eac5d 100644
--- a/src/main/java/com/checkout/handlepaymentsandpayouts/flow/requests/PaymentSessionInfo.java
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/flow/requests/PaymentSessionInfo.java
@@ -33,94 +33,116 @@
 public abstract class PaymentSessionInfo extends PaymentSessionBase {
 
     /**
-     * The three-letter ISO currency code
+     * The three-letter ISO currency code.
+     * [Optional]
+     * min 3 max 3
      */
     private Currency currency;
 
     /**
      * The billing details.
+     * [Optional]
      */
     private BillingInformation billing;
 
     /**
-     * Overrides the default success redirect URL configured on your account, 
+     * Overrides the default success redirect URL configured on your account,
      * for payment methods that require a redirect.
+     * [Optional]
+     * Format: uri
      */
     private String successUrl;
 
     /**
-     * Overrides the default failure redirect URL configured on your account, 
+     * Overrides the default failure redirect URL configured on your account,
      * for payment methods that require a redirect.
+     * [Optional]
+     * Format: uri
      */
     private String failureUrl;
 
     /**
      * A description of the purchase, which is displayed on the customer's statement.
+     * [Optional]
      */
     private BillingDescriptor billingDescriptor;
 
     /**
      * A description for the payment.
+     * [Optional]
      */
     private String description;
 
     /**
      * The customer's details. Required if source.type is tamara.
+     * [Optional]
      */
     private Customer customer;
 
     /**
-     * The shipping details
+     * The shipping details.
+     * [Optional]
      */
     private ShippingDetails shipping;
 
     /**
      * Information about the recipient of the payment's funds.
+     * [Optional]
      */
     private PaymentRecipient recipient;
 
     /**
-     * Use the processing object to influence or override the data sent during card processing
+     * Use the processing object to influence or override the data sent during card processing.
+     * [Optional]
      */
     private ProcessingSettings processing;
 
     /**
      * Details about the payment instruction.
+     * [Optional]
      */
     private PaymentInstruction instruction;
 
     /**
      * The processing channel to use for the payment.
+     * [Optional]
+     * Pattern: ^(pc)_(\w{26})$
      */
     private String processingChannelId;
 
     /**
      * The sub-entities that the payment is being processed on behalf of.
+     * [Optional]
      */
     private List<AmountAllocations> amountAllocations;
 
     /**
      * Configures the risk assessment performed during payment processing.
+     * [Optional]
      */
     private RiskRequest risk;
 
     /**
      * The merchant's display name.
+     * [Optional]
      */
     private String displayName;
 
     /**
      * Allows you to store additional information about a transaction with custom fields.
+     * [Optional]
      */
     private Map<String, Object> metadata;
 
     /**
      * The sender of the payment.
+     * [Optional]
      */
     private PaymentSender sender;
 
     /**
      * Specifies whether to capture the payment, if applicable. Default: true
+     * [Optional]
      */
     @Builder.Default
     private Boolean capture = true;
@@ -128,6 +150,8 @@ public abstract class PaymentSessionInfo extends PaymentSessionBase {
     /**
      * A timestamp specifying when to capture the payment, as an ISO 8601 code.
      * If a value is provided, capture is automatically set to true.
+     * [Optional]
+     * Format: date-time (ISO 8601)
      */
     private Instant captureOn;
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/flow/requests/PaymentSessionSubmitRequest.java b/src/main/java/com/checkout/handlepaymentsandpayouts/flow/requests/PaymentSessionSubmitRequest.java
index fbfd45b4..8bc91a20 100644
--- a/src/main/java/com/checkout/handlepaymentsandpayouts/flow/requests/PaymentSessionSubmitRequest.java
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/flow/requests/PaymentSessionSubmitRequest.java
@@ -9,7 +9,7 @@
 
 /**
  * Request to submit a payment session.
- * 
+ *
  * This request works with the Flow handleSubmit callback, where you can perform a customized payment submission.
  * You must send the unmodified response body as the response of the handleSubmit callback.
  */
@@ -21,20 +21,23 @@
 public final class PaymentSessionSubmitRequest extends PaymentSessionInfo {
 
     /**
-     * A unique token representing the additional customer data captured by Flow, 
+     * A unique token representing the additional customer data captured by Flow,
      * as received from the handleSubmit callback.
      * Do not log or store this value.
+     * [Optional]
      */
     private String sessionData;
 
     /**
      * Configurations for payment method-specific settings.
+     * [Optional]
      */
     private PaymentMethodConfiguration paymentMethodConfiguration;
 
     /**
      * Deprecated - The Customer's IP address. Only IPv4 and IPv6 addresses are accepted.
+     * [Optional]
      */
     @Deprecated
     private String ipAddress;
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/flow/responses/ActionRequiredPaymentSubmissionResponse.java b/src/main/java/com/checkout/handlepaymentsandpayouts/flow/responses/ActionRequiredPaymentSubmissionResponse.java
index a6893532..e555037d 100644
--- a/src/main/java/com/checkout/handlepaymentsandpayouts/flow/responses/ActionRequiredPaymentSubmissionResponse.java
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/flow/responses/ActionRequiredPaymentSubmissionResponse.java
@@ -1,7 +1,6 @@
 package com.checkout.handlepaymentsandpayouts.flow.responses;
 
 import com.checkout.handlepaymentsandpayouts.flow.entities.PaymentAction;
-import com.google.gson.annotations.SerializedName;
 import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Data;
@@ -20,17 +19,20 @@ public final class ActionRequiredPaymentSubmissionResponse extends PaymentSubmis
 
     /**
      * Instruction for further payment action.
+     * [Optional]
      */
     private PaymentAction action;
 
     /**
-     * The Payment Sessions unique identifier (only present in CreateAndSubmitPaymentSession response)
+     * The Payment Sessions unique identifier (only present in CreateAndSubmitPaymentSession response).
+     * [Optional]
      */
     private String paymentSessionId;
 
     /**
      * The secret used by Flow to authenticate payment session requests (only present in CreateAndSubmitPaymentSession response).
      * Do not log or store this value.
+     * [Optional]
      */
     private String paymentSessionSecret;
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/flow/responses/ApprovedPaymentSubmissionResponse.java b/src/main/java/com/checkout/handlepaymentsandpayouts/flow/responses/ApprovedPaymentSubmissionResponse.java
index eb6603c2..9d3e6e66 100644
--- a/src/main/java/com/checkout/handlepaymentsandpayouts/flow/responses/ApprovedPaymentSubmissionResponse.java
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/flow/responses/ApprovedPaymentSubmissionResponse.java
@@ -1,6 +1,5 @@
 package com.checkout.handlepaymentsandpayouts.flow.responses;
 
-import com.google.gson.annotations.SerializedName;
 import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Data;
@@ -18,13 +17,15 @@
 public final class ApprovedPaymentSubmissionResponse extends PaymentSubmissionResponse {
 
     /**
-     * The Payment Sessions unique identifier (only present in CreateAndSubmitPaymentSession response)
+     * The Payment Sessions unique identifier (only present in CreateAndSubmitPaymentSession response).
+     * [Optional]
      */
     private String paymentSessionId;
 
     /**
      * The secret used by Flow to authenticate payment session requests (only present in CreateAndSubmitPaymentSession response).
      * Do not log or store this value.
+     * [Optional]
      */
     private String paymentSessionSecret;
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/flow/responses/DeclinedPaymentSubmissionResponse.java b/src/main/java/com/checkout/handlepaymentsandpayouts/flow/responses/DeclinedPaymentSubmissionResponse.java
index 5c14367f..3eac8166 100644
--- a/src/main/java/com/checkout/handlepaymentsandpayouts/flow/responses/DeclinedPaymentSubmissionResponse.java
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/flow/responses/DeclinedPaymentSubmissionResponse.java
@@ -18,6 +18,7 @@ public final class DeclinedPaymentSubmissionResponse extends PaymentSubmissionRe
 
     /**
      * The reason for the payment decline.
+     * [Optional]
      */
     private String declineReason;
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/flow/responses/PaymentSessionResponse.java b/src/main/java/com/checkout/handlepaymentsandpayouts/flow/responses/PaymentSessionResponse.java
index 2cef1fd8..125d10de 100644
--- a/src/main/java/com/checkout/handlepaymentsandpayouts/flow/responses/PaymentSessionResponse.java
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/flow/responses/PaymentSessionResponse.java
@@ -1,7 +1,6 @@
 package com.checkout.handlepaymentsandpayouts.flow.responses;
 
 import com.checkout.common.Resource;
-import com.google.gson.annotations.SerializedName;
 import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Data;
@@ -19,19 +18,22 @@
 public final class PaymentSessionResponse extends Resource {
 
     /**
-     * The Payment Sessions unique identifier
+     * The Payment Sessions unique identifier.
+     * [Optional]
      */
     private String id;
 
     /**
      * A unique token representing the payment session, which you must provide when you initialize Flow.
      * Do not log or store this value.
+     * [Optional]
      */
     private String paymentSessionToken;
 
     /**
      * The secret used by Flow to authenticate payment session requests.
      * Do not log or store this value.
+     * [Optional]
      */
     private String paymentSessionSecret;
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/flow/responses/PaymentSubmissionResponse.java b/src/main/java/com/checkout/handlepaymentsandpayouts/flow/responses/PaymentSubmissionResponse.java
index 557e18dc..cb2fd84c 100644
--- a/src/main/java/com/checkout/handlepaymentsandpayouts/flow/responses/PaymentSubmissionResponse.java
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/flow/responses/PaymentSubmissionResponse.java
@@ -17,16 +17,19 @@ public abstract class PaymentSubmissionResponse extends Resource {
 
     /**
      * The payment identifier.
+     * [Optional]
      */
     private String id;
 
     /**
      * The payment's status - used for polymorphic deserialization.
+     * [Optional]
      */
     private PaymentSessionStatus status;
 
     /**
      * The payment method name.
+     * [Optional]
      */
     private PaymentMethodType type;
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/billing/PaymentSetupBilling.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/billing/PaymentSetupBilling.java
new file mode 100644
index 00000000..02e28737
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/billing/PaymentSetupBilling.java
@@ -0,0 +1,22 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.billing;
+
+import com.checkout.common.Address;
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+/**
+ * The billing details for the payment setup.
+ */
+@Data
+@Builder
+@NoArgsConstructor
+@AllArgsConstructor
+public final class PaymentSetupBilling {
+
+    /**
+     * The billing address.
+     */
+    private Address address;
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/PaymentMethods.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/PaymentMethods.java
index 93cb3cee..4e8ed4bf 100644
--- a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/PaymentMethods.java
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/PaymentMethods.java
@@ -1,17 +1,49 @@
 package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods;
 
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.ach.Ach;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.alipay.AlipayCn;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.alipay.AlipayHk;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.alma.Alma;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.applepay.ApplePay;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.bancontact.Bancontact;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.benefit.Benefit;
 import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.bizum.Bizum;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.card.Card;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.dana.Dana;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.eps.Eps;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.gcash.GCash;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.googlepay.GooglePay;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.ideal.Ideal;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.instrument.Instrument;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.kakaopay.KakaoPay;
 import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.klarna.Klarna;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.knet.Knet;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.mbway.MBWay;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.mobilepay.MobilePay;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.multibanco.Multibanco;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.octopus.Octopus;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.p24.P24;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.paynow.PayNow;
 import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.paypal.PayPal;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.qpay.Qpay;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.sepa.Sepa;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.sequra.Sequra;
 import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.stcpay.Stcpay;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.swish.Swish;
 import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.tabby.Tabby;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.tamara.Tamara;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.tng.Tng;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.truemoney.TrueMoney;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.twint.Twint;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.vipps.Vipps;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.wechatpay.WeChatPay;
 import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Data;
 import lombok.NoArgsConstructor;
 
 /**
- * Payment methods configuration
+ * Payment methods configuration for a payment setup.
  */
 @Data
 @Builder
@@ -20,27 +52,224 @@
 public final class PaymentMethods {
 
     /**
-     * Klarna payment method configuration
+     * Instrument (saved payment source) configuration.
+     * [Optional]
+     */
+    private Instrument instrument;
+
+    /**
+     * Klarna payment method configuration.
+     * [Optional]
      */
     private Klarna klarna;
 
     /**
-     * STC Pay payment method configuration
+     * STC Pay payment method configuration.
+     * [Optional]
      */
     private Stcpay stcpay;
 
     /**
-     * Tabby payment method configuration
+     * Tabby payment method configuration.
+     * [Optional]
      */
     private Tabby tabby;
 
     /**
-     * PayPal payment method configuration
+     * PayPal payment method configuration.
+     * [Optional]
      */
     private PayPal paypal;
 
     /**
-     * Bizum payment method configuration
+     * Bizum payment method configuration.
+     * [Optional]
      */
     private Bizum bizum;
-}
\ No newline at end of file
+
+    /**
+     * PayNow payment method configuration.
+     * [Optional]
+     */
+    private PayNow paynow;
+
+    /**
+     * QPay payment method configuration.
+     * [Optional]
+     */
+    private Qpay qpay;
+
+    /**
+     * EPS payment method configuration.
+     * [Optional]
+     */
+    private Eps eps;
+
+    /**
+     * iDEAL payment method configuration.
+     * [Optional]
+     */
+    private Ideal ideal;
+
+    /**
+     * KNET payment method configuration.
+     * [Optional]
+     */
+    private Knet knet;
+
+    /**
+     * Bancontact payment method configuration.
+     * [Optional]
+     */
+    private Bancontact bancontact;
+
+    /**
+     * Benefit payment method configuration.
+     * [Optional]
+     */
+    private Benefit benefit;
+
+    /**
+     * Vipps payment method configuration.
+     * [Optional]
+     */
+    private Vipps vipps;
+
+    /**
+     * Twint payment method configuration.
+     * [Optional]
+     */
+    private Twint twint;
+
+    /**
+     * Alipay CN payment method configuration.
+     * [Optional]
+     */
+    private AlipayCn alipayCn;
+
+    /**
+     * Alipay HK payment method configuration.
+     * [Optional]
+     */
+    private AlipayHk alipayHk;
+
+    /**
+     * GCash payment method configuration.
+     * [Optional]
+     */
+    private GCash gcash;
+
+    /**
+     * TNG payment method configuration.
+     * [Optional]
+     */
+    private Tng tng;
+
+    /**
+     * Dana payment method configuration.
+     * [Optional]
+     */
+    private Dana dana;
+
+    /**
+     * MobilePay payment method configuration.
+     * [Optional]
+     */
+    private MobilePay mobilepay;
+
+    /**
+     * Tamara payment method configuration.
+     * [Optional]
+     */
+    private Tamara tamara;
+
+    /**
+     * MBWay payment method configuration.
+     * [Optional]
+     */
+    private MBWay mbway;
+
+    /**
+     * Multibanco payment method configuration.
+     * [Optional]
+     */
+    private Multibanco multibanco;
+
+    /**
+     * WeChatPay payment method configuration.
+     * [Optional]
+     */
+    private WeChatPay wechatpay;
+
+    /**
+     * KakaoPay payment method configuration.
+     * [Optional]
+     */
+    private KakaoPay kakaopay;
+
+    /**
+     * TrueMoney payment method configuration.
+     * [Optional]
+     */
+    private TrueMoney truemoney;
+
+    /**
+     * Octopus payment method configuration.
+     * [Optional]
+     */
+    private Octopus octopus;
+
+    /**
+     * P24 (Przelewy24) payment method configuration.
+     * [Optional]
+     */
+    private P24 p24;
+
+    /**
+     * Alma payment method configuration.
+     * [Optional]
+     */
+    private Alma alma;
+
+    /**
+     * Swish payment method configuration.
+     * [Optional]
+     */
+    private Swish swish;
+
+    /**
+     * Sequra payment method configuration.
+     * [Optional]
+     */
+    private Sequra sequra;
+
+    /**
+     * ACH (Direct Debit) payment method configuration.
+     * [Optional]
+     */
+    private Ach ach;
+
+    /**
+     * SEPA (Direct Debit) payment method configuration.
+     * [Optional]
+     */
+    private Sepa sepa;
+
+    /**
+     * GooglePay payment method configuration.
+     * [Optional]
+     */
+    private GooglePay googlepay;
+
+    /**
+     * ApplePay payment method configuration.
+     * [Optional]
+     */
+    private ApplePay applepay;
+
+    /**
+     * Card payment method configuration.
+     * [Optional]
+     */
+    private Card card;
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/ach/Ach.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/ach/Ach.java
new file mode 100644
index 00000000..6fb15431
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/ach/Ach.java
@@ -0,0 +1,46 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.ach;
+
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.PaymentMethodBase;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+/**
+ * The ACH payment method's details and configuration.
+ */
+@Data
+@EqualsAndHashCode(callSuper = true)
+public final class Ach extends PaymentMethodBase {
+
+    /**
+     * The type of Direct Debit account.
+     * [Optional]
+     */
+    private AchAccountType accountType;
+
+    /**
+     * The account holder details.
+     * [Optional]
+     */
+    private AchAccountHolder accountHolder;
+
+    /**
+     * The account number of the Direct Debit account.
+     * [Optional]
+     * min 4 characters, max 17 characters
+     */
+    private String accountNumber;
+
+    /**
+     * The bank code of the Direct Debit account.
+     * [Optional]
+     * min 8 characters, max 9 characters
+     */
+    private String bankCode;
+
+    /**
+     * The two-letter ISO country code of the bank account.
+     * [Optional]
+     * max 2 characters
+     */
+    private String country;
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/ach/AchAccountHolder.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/ach/AchAccountHolder.java
new file mode 100644
index 00000000..b5cbeef4
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/ach/AchAccountHolder.java
@@ -0,0 +1,53 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.ach;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+/**
+ * The ACH account holder details.
+ */
+@Data
+@Builder
+@NoArgsConstructor
+@AllArgsConstructor
+public final class AchAccountHolder {
+
+    /**
+     * The type of account holder.
+     * [Optional]
+     */
+    private AchAccountHolderType type;
+
+    /**
+     * The first name of the account holder.
+     * [Optional]
+     */
+    private String firstName;
+
+    /**
+     * The last name of the account holder.
+     * [Optional]
+     */
+    private String lastName;
+
+    /**
+     * The legal name of a registered company that holds the account.
+     * [Optional]
+     */
+    private String companyName;
+
+    /**
+     * The account holder's date of birth.
+     * [Optional]
+     * Format: yyyy-MM-dd
+     */
+    private String dateOfBirth;
+
+    /**
+     * The account holder's government document identification.
+     * [Optional]
+     */
+    private AchIdentification identification;
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/ach/AchAccountHolderType.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/ach/AchAccountHolderType.java
new file mode 100644
index 00000000..a065458f
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/ach/AchAccountHolderType.java
@@ -0,0 +1,18 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.ach;
+
+import com.google.gson.annotations.SerializedName;
+
+/**
+ * The type of account holder.
+ */
+public enum AchAccountHolderType {
+
+    @SerializedName("individual")
+    INDIVIDUAL,
+
+    @SerializedName("corporate")
+    CORPORATE,
+
+    @SerializedName("government")
+    GOVERNMENT
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/ach/AchAccountType.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/ach/AchAccountType.java
new file mode 100644
index 00000000..bbd95284
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/ach/AchAccountType.java
@@ -0,0 +1,18 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.ach;
+
+import com.google.gson.annotations.SerializedName;
+
+/**
+ * The type of Direct Debit account.
+ */
+public enum AchAccountType {
+
+    @SerializedName("savings")
+    SAVINGS,
+
+    @SerializedName("current")
+    CURRENT,
+
+    @SerializedName("cash")
+    CASH
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/ach/AchIdentification.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/ach/AchIdentification.java
new file mode 100644
index 00000000..af8096b9
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/ach/AchIdentification.java
@@ -0,0 +1,34 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.ach;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+/**
+ * The account holder's government document identification.
+ */
+@Data
+@Builder
+@NoArgsConstructor
+@AllArgsConstructor
+public final class AchIdentification {
+
+    /**
+     * The document type.
+     * [Optional]
+     */
+    private String type;
+
+    /**
+     * The country where the document was issued.
+     * [Optional]
+     */
+    private String issuingCountry;
+
+    /**
+     * The document number.
+     * [Optional]
+     */
+    private String number;
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/alipay/AlipayCn.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/alipay/AlipayCn.java
new file mode 100644
index 00000000..1686e69f
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/alipay/AlipayCn.java
@@ -0,0 +1,29 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.alipay;
+
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.OsType;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.PaymentMethodBase;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.TerminalType;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+/**
+ * The Alipay CN payment method's details and configuration.
+ */
+@Data
+@EqualsAndHashCode(callSuper = true)
+public final class AlipayCn extends PaymentMethodBase {
+
+    /**
+     * The client-side terminal type.
+     * [Optional]
+     * Enum: "APP" "WAP" "WEB"
+     */
+    private TerminalType terminalType;
+
+    /**
+     * The customer's operating system type. Required when terminal_type is not WEB.
+     * [Optional]
+     * Enum: "ANDROID" "IOS"
+     */
+    private OsType osType;
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/alipay/AlipayHk.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/alipay/AlipayHk.java
new file mode 100644
index 00000000..6c082815
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/alipay/AlipayHk.java
@@ -0,0 +1,29 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.alipay;
+
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.OsType;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.PaymentMethodBase;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.TerminalType;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+/**
+ * The Alipay HK payment method's details and configuration.
+ */
+@Data
+@EqualsAndHashCode(callSuper = true)
+public final class AlipayHk extends PaymentMethodBase {
+
+    /**
+     * The client-side terminal type.
+     * [Optional]
+     * Enum: "APP" "WAP" "WEB"
+     */
+    private TerminalType terminalType;
+
+    /**
+     * The customer's operating system type. Required when terminal_type is not WEB.
+     * [Optional]
+     * Enum: "ANDROID" "IOS"
+     */
+    private OsType osType;
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/alma/Alma.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/alma/Alma.java
new file mode 100644
index 00000000..45dc432c
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/alma/Alma.java
@@ -0,0 +1,13 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.alma;
+
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.PaymentMethodBase;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+/**
+ * The Alma payment method's details and configuration.
+ */
+@Data
+@EqualsAndHashCode(callSuper = true)
+public final class Alma extends PaymentMethodBase {
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/applepay/ApplePay.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/applepay/ApplePay.java
new file mode 100644
index 00000000..82b2195b
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/applepay/ApplePay.java
@@ -0,0 +1,54 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.applepay;
+
+import com.checkout.common.Phone;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.CardAccountHolder;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.PaymentMethodBase;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+import java.time.Instant;
+
+/**
+ * The Apple Pay payment method's details and configuration.
+ */
+@Data
+@EqualsAndHashCode(callSuper = true)
+public final class ApplePay extends PaymentMethodBase {
+
+    /**
+     * The Apple Pay encrypted payment token data.
+     * [Optional]
+     */
+    private ApplePayTokenData tokenData;
+
+    /**
+     * The Apple Pay payment token string.
+     * [Optional]
+     */
+    private String token;
+
+    /**
+     * The date and time the token expires.
+     * [Optional]
+     * Format: date-time (ISO 8601)
+     */
+    private Instant expiresOn;
+
+    /**
+     * Set to true if you intend to reuse the payment credentials in subsequent payments.
+     * [Optional]
+     */
+    private Boolean storeForFutureUse;
+
+    /**
+     * The customer's phone number.
+     * [Optional]
+     */
+    private Phone phone;
+
+    /**
+     * The card account holder details.
+     * [Optional]
+     */
+    private CardAccountHolder accountHolder;
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/applepay/ApplePayTokenData.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/applepay/ApplePayTokenData.java
new file mode 100644
index 00000000..85a2f841
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/applepay/ApplePayTokenData.java
@@ -0,0 +1,40 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.applepay;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+/**
+ * The Apple Pay encrypted payment token data.
+ */
+@Data
+@Builder
+@NoArgsConstructor
+@AllArgsConstructor
+public final class ApplePayTokenData {
+
+    /**
+     * The version of the payment token: EC_v1 for ECC-encrypted data, RSA_v1 for RSA-encrypted data.
+     * [Optional]
+     */
+    private String version;
+
+    /**
+     * The encrypted payment data, Base64-encoded.
+     * [Optional]
+     */
+    private String data;
+
+    /**
+     * The signature of the payment and header data.
+     * [Optional]
+     */
+    private String signature;
+
+    /**
+     * Additional version-dependent information used to decrypt and verify the payment.
+     * [Optional]
+     */
+    private ApplePayTokenDataHeader header;
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/applepay/ApplePayTokenDataHeader.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/applepay/ApplePayTokenDataHeader.java
new file mode 100644
index 00000000..a57d996a
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/applepay/ApplePayTokenDataHeader.java
@@ -0,0 +1,34 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.applepay;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+/**
+ * Additional version-dependent information used to decrypt and verify the Apple Pay payment.
+ */
+@Data
+@Builder
+@NoArgsConstructor
+@AllArgsConstructor
+public final class ApplePayTokenDataHeader {
+
+    /**
+     * The ephemeral public key bytes.
+     * [Optional]
+     */
+    private String ephemeralPublicKey;
+
+    /**
+     * The hash of the X.509 encoded public key bytes of the merchant's certificate.
+     * [Optional]
+     */
+    private String publicKeyHash;
+
+    /**
+     * The transaction identifier, generated on the device.
+     * [Optional]
+     */
+    private String transactionId;
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/bancontact/Bancontact.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/bancontact/Bancontact.java
new file mode 100644
index 00000000..b7ef329e
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/bancontact/Bancontact.java
@@ -0,0 +1,20 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.bancontact;
+
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.PaymentMethodBase;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+/**
+ * The Bancontact payment method's details and configuration.
+ */
+@Data
+@EqualsAndHashCode(callSuper = true)
+public final class Bancontact extends PaymentMethodBase {
+
+    /**
+     * The account holder's name.
+     * [Optional]
+     * min 3 characters, max 100 characters
+     */
+    private String accountHolderName;
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/benefit/Benefit.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/benefit/Benefit.java
new file mode 100644
index 00000000..55adfd46
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/benefit/Benefit.java
@@ -0,0 +1,13 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.benefit;
+
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.PaymentMethodBase;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+/**
+ * The Benefit payment method's details and configuration.
+ */
+@Data
+@EqualsAndHashCode(callSuper = true)
+public final class Benefit extends PaymentMethodBase {
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/card/Card.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/card/Card.java
new file mode 100644
index 00000000..d2956f63
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/card/Card.java
@@ -0,0 +1,102 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.card;
+
+import com.checkout.common.Phone;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.CardAccountHolder;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.PaymentMethodBase;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+import java.time.Instant;
+
+/**
+ * The Card payment method's details and configuration.
+ */
+@Data
+@EqualsAndHashCode(callSuper = true)
+public final class Card extends PaymentMethodBase {
+
+    /**
+     * The card number (without separators). Write-only.
+     * [Optional]
+     */
+    private String number;
+
+    /**
+     * The last four digits of the card number. Read-only.
+     * [Optional]
+     */
+    private String last4;
+
+    /**
+     * The card issuer's Bank Identification Number (BIN). Read-only.
+     * [Optional]
+     */
+    private String bin;
+
+    /**
+     * The card scheme. Read-only.
+     * [Optional]
+     */
+    private String scheme;
+
+    /**
+     * The expiry month of the card.
+     * [Optional]
+     */
+    private Integer expiryMonth;
+
+    /**
+     * The expiry year of the card.
+     * [Optional]
+     */
+    private Integer expiryYear;
+
+    /**
+     * The cardholder's name. Write-only.
+     * [Optional]
+     */
+    private String name;
+
+    /**
+     * The card verification value/code. 3 digits, except for American Express (4 digits). Write-only.
+     * [Optional]
+     */
+    private String cvv;
+
+    /**
+     * Set to true for payments that use stored card details. Write-only.
+     * [Optional]
+     */
+    private Boolean stored;
+
+    /**
+     * The time by which the card details must be confirmed. Read-only.
+     * [Optional]
+     * Format: date-time (ISO 8601)
+     */
+    private Instant expiresOn;
+
+    /**
+     * Set to true if you intend to reuse the payment credentials in subsequent payments. Write-only.
+     * [Optional]
+     */
+    private Boolean storeForFutureUse;
+
+    /**
+     * The customer's phone number.
+     * [Optional]
+     */
+    private Phone phone;
+
+    /**
+     * The card account holder details.
+     * [Optional]
+     */
+    private CardAccountHolder accountHolder;
+
+    /**
+     * Indicates whether to use the Real-Time Account Updater to update the card information.
+     * [Optional]
+     */
+    private Boolean allowUpdate;
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/common/CardAccountHolder.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/common/CardAccountHolder.java
new file mode 100644
index 00000000..3f9c1669
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/common/CardAccountHolder.java
@@ -0,0 +1,46 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+/**
+ * Card account holder information, shared by Card, GooglePay, and ApplePay payment methods.
+ */
+@Data
+@Builder
+@NoArgsConstructor
+@AllArgsConstructor
+public final class CardAccountHolder {
+
+    /**
+     * The card account holder type.
+     * [Optional]
+     */
+    private CardAccountHolderType type;
+
+    /**
+     * The card account holder's first name.
+     * [Optional]
+     */
+    private String firstName;
+
+    /**
+     * The card account holder's last name.
+     * [Optional]
+     */
+    private String lastName;
+
+    /**
+     * The card account holder's middle name.
+     * [Optional]
+     */
+    private String middleName;
+
+    /**
+     * Indicates whether the ANI (account name inquiry) check is performed with the card scheme.
+     * [Optional]
+     */
+    private Boolean accountNameInquiry;
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/common/CardAccountHolderType.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/common/CardAccountHolderType.java
new file mode 100644
index 00000000..af0815fa
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/common/CardAccountHolderType.java
@@ -0,0 +1,18 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common;
+
+import com.google.gson.annotations.SerializedName;
+
+/**
+ * The card account holder type.
+ */
+public enum CardAccountHolderType {
+
+    @SerializedName("individual")
+    INDIVIDUAL,
+
+    @SerializedName("government")
+    GOVERNMENT,
+
+    @SerializedName("corporate")
+    CORPORATE
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/common/OsType.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/common/OsType.java
new file mode 100644
index 00000000..293c8ca7
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/common/OsType.java
@@ -0,0 +1,15 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common;
+
+import com.google.gson.annotations.SerializedName;
+
+/**
+ * The customer's operating system type. Required when terminal_type is not web.
+ */
+public enum OsType {
+
+    @SerializedName("android")
+    ANDROID,
+
+    @SerializedName("ios")
+    IOS
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/common/PaymentMethodAction.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/common/PaymentMethodAction.java
index 52bea3d9..d844fa76 100644
--- a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/common/PaymentMethodAction.java
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/common/PaymentMethodAction.java
@@ -1,13 +1,12 @@
 package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common;
 
-import com.google.gson.annotations.SerializedName;
 import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Data;
 import lombok.NoArgsConstructor;
 
 /**
- * Next-step action returned by the API for a payment method (read-only).
+ * Next-step action returned by the API for a payment method.
  */
 @Data
 @Builder
@@ -16,30 +15,26 @@
 public final class PaymentMethodAction {
 
     /**
-     * The type of action.
-     * <p>[Read-only]</p>
-     * {@code sdk} or {@code otp} (varies by payment method).
+     * The type of action: sdk or otp (varies by payment method).
+     * [Optional]
      */
     private String type;
 
     /**
      * The client token for the Klarna or PayPal SDK.
-     * <p>[Read-only]</p>
+     * [Optional]
      */
-    @SerializedName("client_token")
     private String clientToken;
 
     /**
      * The session identifier for the Klarna payment method session.
-     * <p>[Read-only]</p>
+     * [Optional]
      */
-    @SerializedName("session_id")
     private String sessionId;
 
     /**
      * The PayPal order ID to use with the PayPal SDK.
-     * <p>[Read-only]</p>
+     * [Optional]
      */
-    @SerializedName("order_id")
     private String orderId;
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/common/PaymentMethodBase.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/common/PaymentMethodBase.java
index db991007..18422d00 100644
--- a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/common/PaymentMethodBase.java
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/common/PaymentMethodBase.java
@@ -12,13 +12,13 @@ public abstract class PaymentMethodBase {
 
     /**
      * The payment method status.
-     * <p>[Read-only]</p>
+     * [Optional]
      */
     private PaymentMethodStatus status;
 
     /**
      * An array of error codes or indicators that highlight missing or invalid information.
-     * <p>[Read-only]</p>
+     * [Optional]
      */
     private List<String> flags;
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/common/TerminalType.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/common/TerminalType.java
new file mode 100644
index 00000000..4e115e24
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/common/TerminalType.java
@@ -0,0 +1,19 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common;
+
+import com.google.gson.annotations.SerializedName;
+
+/**
+ * The client-side terminal type. Indicates whether the customer is using a PC browser,
+ * mobile browser, or mobile application.
+ */
+public enum TerminalType {
+
+    @SerializedName("web")
+    WEB,
+
+    @SerializedName("wap")
+    WAP,
+
+    @SerializedName("app")
+    APP
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/dana/Dana.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/dana/Dana.java
new file mode 100644
index 00000000..2b754c27
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/dana/Dana.java
@@ -0,0 +1,29 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.dana;
+
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.OsType;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.PaymentMethodBase;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.TerminalType;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+/**
+ * The Dana payment method's details and configuration.
+ */
+@Data
+@EqualsAndHashCode(callSuper = true)
+public final class Dana extends PaymentMethodBase {
+
+    /**
+     * The client-side terminal type.
+     * [Optional]
+     * Enum: "APP" "WAP" "WEB"
+     */
+    private TerminalType terminalType;
+
+    /**
+     * The customer's operating system type. Required when terminal_type is not WEB.
+     * [Optional]
+     * Enum: "ANDROID" "IOS"
+     */
+    private OsType osType;
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/eps/Eps.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/eps/Eps.java
new file mode 100644
index 00000000..5de48a56
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/eps/Eps.java
@@ -0,0 +1,13 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.eps;
+
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.PaymentMethodBase;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+/**
+ * The EPS payment method's details and configuration.
+ */
+@Data
+@EqualsAndHashCode(callSuper = true)
+public final class Eps extends PaymentMethodBase {
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/gcash/GCash.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/gcash/GCash.java
new file mode 100644
index 00000000..1b339d9b
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/gcash/GCash.java
@@ -0,0 +1,29 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.gcash;
+
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.OsType;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.PaymentMethodBase;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.TerminalType;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+/**
+ * The GCash payment method's details and configuration.
+ */
+@Data
+@EqualsAndHashCode(callSuper = true)
+public final class GCash extends PaymentMethodBase {
+
+    /**
+     * The client-side terminal type.
+     * [Optional]
+     * Enum: "APP" "WAP" "WEB"
+     */
+    private TerminalType terminalType;
+
+    /**
+     * The customer's operating system type. Required when terminal_type is not WEB.
+     * [Optional]
+     * Enum: "ANDROID" "IOS"
+     */
+    private OsType osType;
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/googlepay/GooglePay.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/googlepay/GooglePay.java
new file mode 100644
index 00000000..abdc9737
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/googlepay/GooglePay.java
@@ -0,0 +1,54 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.googlepay;
+
+import com.checkout.common.Phone;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.CardAccountHolder;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.PaymentMethodBase;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+import java.time.Instant;
+
+/**
+ * The Google Pay payment method's details and configuration.
+ */
+@Data
+@EqualsAndHashCode(callSuper = true)
+public final class GooglePay extends PaymentMethodBase {
+
+    /**
+     * The Google Pay encrypted payment token data.
+     * [Optional]
+     */
+    private GooglePayTokenData tokenData;
+
+    /**
+     * The Google Pay payment token string.
+     * [Optional]
+     */
+    private String token;
+
+    /**
+     * The date and time the token expires.
+     * [Optional]
+     * Format: date-time (ISO 8601)
+     */
+    private Instant expiresOn;
+
+    /**
+     * Set to true if you intend to reuse the payment credentials in subsequent payments.
+     * [Optional]
+     */
+    private Boolean storeForFutureUse;
+
+    /**
+     * The customer's phone number.
+     * [Optional]
+     */
+    private Phone phone;
+
+    /**
+     * The card account holder details.
+     * [Optional]
+     */
+    private CardAccountHolder accountHolder;
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/googlepay/GooglePayTokenData.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/googlepay/GooglePayTokenData.java
new file mode 100644
index 00000000..9450eb69
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/googlepay/GooglePayTokenData.java
@@ -0,0 +1,40 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.googlepay;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+/**
+ * The Google Pay payment token data.
+ */
+@Data
+@Builder
+@NoArgsConstructor
+@AllArgsConstructor
+public final class GooglePayTokenData {
+
+    /**
+     * The encryption and signing scheme used to create this message. Defaults to ECv0.
+     * [Optional]
+     */
+    private String protocolVersion;
+
+    /**
+     * The signature that verifies the message came from Google, created using ECDSA.
+     * [Optional]
+     */
+    private String signature;
+
+    /**
+     * A serialized JSON string containing the encryptedMessage, ephemeralPublicKey, and tag.
+     * [Optional]
+     */
+    private String signedMessage;
+
+    /**
+     * The public key provided to the Google API in the tokenizationSpecification.parameters field.
+     * [Optional]
+     */
+    private String tokenizationKey;
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/ideal/Ideal.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/ideal/Ideal.java
new file mode 100644
index 00000000..dc6ef3a5
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/ideal/Ideal.java
@@ -0,0 +1,21 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.ideal;
+
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.PaymentMethodBase;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+/**
+ * The iDEAL payment method's details and configuration.
+ */
+@Data
+@EqualsAndHashCode(callSuper = true)
+public final class Ideal extends PaymentMethodBase {
+
+    /**
+     * A description of the products or services being paid for.
+     * Do not include HTML tags or special characters.
+     * [Optional]
+     * max 35 characters
+     */
+    private String description;
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/instrument/Instrument.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/instrument/Instrument.java
new file mode 100644
index 00000000..d04e0c15
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/instrument/Instrument.java
@@ -0,0 +1,26 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.instrument;
+
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.PaymentMethodBase;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.PaymentMethodAction;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+/**
+ * The instrument payment method's details and configuration.
+ */
+@Data
+@EqualsAndHashCode(callSuper = true)
+public final class Instrument extends PaymentMethodBase {
+
+    /**
+     * The unique identifier of the selected instrument.
+     * [Optional]
+     */
+    private String id;
+
+    /**
+     * The next available action for the payment method.
+     * [Optional]
+     */
+    private PaymentMethodAction action;
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/kakaopay/KakaoPay.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/kakaopay/KakaoPay.java
new file mode 100644
index 00000000..bc3faedd
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/kakaopay/KakaoPay.java
@@ -0,0 +1,29 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.kakaopay;
+
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.OsType;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.PaymentMethodBase;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.TerminalType;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+/**
+ * The KakaoPay payment method's details and configuration.
+ */
+@Data
+@EqualsAndHashCode(callSuper = true)
+public final class KakaoPay extends PaymentMethodBase {
+
+    /**
+     * The client-side terminal type.
+     * [Optional]
+     * Enum: "APP" "WAP" "WEB"
+     */
+    private TerminalType terminalType;
+
+    /**
+     * The customer's operating system type. Required when terminal_type is not WEB.
+     * [Optional]
+     * Enum: "ANDROID" "IOS"
+     */
+    private OsType osType;
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/klarna/Klarna.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/klarna/Klarna.java
index 3ce72ada..428d2992 100644
--- a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/klarna/Klarna.java
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/klarna/Klarna.java
@@ -15,13 +15,13 @@ public final class Klarna extends PaymentMethodBase {
 
     /**
      * The initialization state of the payment method. Defaults to disabled.
-     * <p>[Optional]</p>
+     * [Optional]
      */
     private PaymentMethodInitialization initialization = PaymentMethodInitialization.DISABLED;
 
     /**
-     * The next available action. Contains type {@code sdk}, {@code client_token}, {@code session_id}.
-     * <p>[Read-only]</p>
+     * The next available action. Contains type, client_token, and session_id.
+     * [Optional]
      */
     private PaymentMethodAction action;
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/klarna/KlarnaAccountHolder.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/klarna/KlarnaAccountHolder.java
index 21f7a19b..7f8d10bc 100644
--- a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/klarna/KlarnaAccountHolder.java
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/klarna/KlarnaAccountHolder.java
@@ -1,14 +1,13 @@
 package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.klarna;
 
 import com.checkout.common.Address;
-import com.google.gson.annotations.SerializedName;
 import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Data;
 import lombok.NoArgsConstructor;
 
 /**
- * Klarna account holder information
+ * Klarna account holder information.
  */
 @Data
 @Builder
@@ -17,8 +16,8 @@
 public final class KlarnaAccountHolder {
 
     /**
-     * The billing address of the Klarna account holder
+     * The billing address of the Klarna account holder.
+     * [Optional]
      */
-    @SerializedName("billing_address")
     private Address billingAddress;
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/knet/Knet.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/knet/Knet.java
new file mode 100644
index 00000000..173c7a99
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/knet/Knet.java
@@ -0,0 +1,19 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.knet;
+
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.PaymentMethodBase;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+/**
+ * The KNET payment method's details and configuration.
+ */
+@Data
+@EqualsAndHashCode(callSuper = true)
+public final class Knet extends PaymentMethodBase {
+
+    /**
+     * The customer's preferred language on the issuer's site.
+     * [Optional]
+     */
+    private KnetLanguage language;
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/knet/KnetLanguage.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/knet/KnetLanguage.java
new file mode 100644
index 00000000..8aabe438
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/knet/KnetLanguage.java
@@ -0,0 +1,15 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.knet;
+
+import com.google.gson.annotations.SerializedName;
+
+/**
+ * The customer's preferred language for KNET payments.
+ */
+public enum KnetLanguage {
+
+    @SerializedName("en")
+    EN,
+
+    @SerializedName("ar")
+    AR
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/mbway/MBWay.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/mbway/MBWay.java
new file mode 100644
index 00000000..0655871d
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/mbway/MBWay.java
@@ -0,0 +1,13 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.mbway;
+
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.PaymentMethodBase;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+/**
+ * The MBWay payment method's details and configuration.
+ */
+@Data
+@EqualsAndHashCode(callSuper = true)
+public final class MBWay extends PaymentMethodBase {
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/mobilepay/MobilePay.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/mobilepay/MobilePay.java
new file mode 100644
index 00000000..597e0512
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/mobilepay/MobilePay.java
@@ -0,0 +1,13 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.mobilepay;
+
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.PaymentMethodBase;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+/**
+ * The MobilePay payment method's details and configuration.
+ */
+@Data
+@EqualsAndHashCode(callSuper = true)
+public final class MobilePay extends PaymentMethodBase {
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/multibanco/Multibanco.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/multibanco/Multibanco.java
new file mode 100644
index 00000000..7d7a2c9b
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/multibanco/Multibanco.java
@@ -0,0 +1,20 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.multibanco;
+
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.PaymentMethodBase;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+/**
+ * The Multibanco payment method's details and configuration.
+ */
+@Data
+@EqualsAndHashCode(callSuper = true)
+public final class Multibanco extends PaymentMethodBase {
+
+    /**
+     * The account holder's name.
+     * [Optional]
+     * min 3 characters, max 100 characters
+     */
+    private String accountHolderName;
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/octopus/Octopus.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/octopus/Octopus.java
new file mode 100644
index 00000000..8c4db543
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/octopus/Octopus.java
@@ -0,0 +1,13 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.octopus;
+
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.PaymentMethodBase;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+/**
+ * The Octopus payment method's details and configuration.
+ */
+@Data
+@EqualsAndHashCode(callSuper = true)
+public final class Octopus extends PaymentMethodBase {
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/p24/P24.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/p24/P24.java
new file mode 100644
index 00000000..1763a6cb
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/p24/P24.java
@@ -0,0 +1,19 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.p24;
+
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.PaymentMethodBase;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+/**
+ * The P24 (Przelewy24) payment method's details and configuration.
+ */
+@Data
+@EqualsAndHashCode(callSuper = true)
+public final class P24 extends PaymentMethodBase {
+
+    /**
+     * The account holder's details.
+     * [Optional]
+     */
+    private P24AccountHolder accountHolder;
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/p24/P24AccountHolder.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/p24/P24AccountHolder.java
new file mode 100644
index 00000000..2aee5637
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/p24/P24AccountHolder.java
@@ -0,0 +1,29 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.p24;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+/**
+ * The P24 account holder's details.
+ */
+@Data
+@Builder
+@NoArgsConstructor
+@AllArgsConstructor
+public final class P24AccountHolder {
+
+    /**
+     * The account holder's name.
+     * [Optional]
+     * min 3 characters, max 100 characters
+     */
+    private String name;
+
+    /**
+     * The account holder's email address.
+     * [Optional]
+     */
+    private String email;
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/paynow/PayNow.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/paynow/PayNow.java
new file mode 100644
index 00000000..7c9f9579
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/paynow/PayNow.java
@@ -0,0 +1,13 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.paynow;
+
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.PaymentMethodBase;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+/**
+ * The PayNow payment method's details and configuration.
+ */
+@Data
+@EqualsAndHashCode(callSuper = true)
+public final class PayNow extends PaymentMethodBase {
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/qpay/Qpay.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/qpay/Qpay.java
new file mode 100644
index 00000000..1b883419
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/qpay/Qpay.java
@@ -0,0 +1,26 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.qpay;
+
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.PaymentMethodBase;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+/**
+ * The QPay payment method's details and configuration.
+ */
+@Data
+@EqualsAndHashCode(callSuper = true)
+public final class Qpay extends PaymentMethodBase {
+
+    /**
+     * The Qatari national ID. Must start with 2 or 3, followed by 10 digits.
+     * [Optional]
+     */
+    private String nationalId;
+
+    /**
+     * A description of the payment order. Alphanumeric characters only.
+     * [Optional]
+     * max 255 characters
+     */
+    private String description;
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/sepa/Sepa.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/sepa/Sepa.java
new file mode 100644
index 00000000..fece1a8c
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/sepa/Sepa.java
@@ -0,0 +1,45 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.sepa;
+
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.PaymentMethodBase;
+import com.checkout.common.Currency;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+/**
+ * The SEPA payment method's details and configuration.
+ */
+@Data
+@EqualsAndHashCode(callSuper = true)
+public final class Sepa extends PaymentMethodBase {
+
+    /**
+     * The account holder details.
+     * [Optional]
+     */
+    private SepaAccountHolder accountHolder;
+
+    /**
+     * The account holder's IBAN.
+     * [Optional]
+     */
+    private String accountNumber;
+
+    /**
+     * The account's country as an ISO 3166-1 alpha-2 code.
+     * [Optional]
+     * max 2 characters
+     */
+    private String country;
+
+    /**
+     * The account holder's account currency.
+     * [Optional]
+     */
+    private Currency currency;
+
+    /**
+     * The SEPA mandate details.
+     * [Optional]
+     */
+    private SepaMandate mandate;
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/sepa/SepaAccountHolder.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/sepa/SepaAccountHolder.java
new file mode 100644
index 00000000..569e3b0d
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/sepa/SepaAccountHolder.java
@@ -0,0 +1,40 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.sepa;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+/**
+ * The SEPA account holder details.
+ */
+@Data
+@Builder
+@NoArgsConstructor
+@AllArgsConstructor
+public final class SepaAccountHolder {
+
+    /**
+     * The type of account holder.
+     * [Optional]
+     */
+    private SepaAccountHolderType type;
+
+    /**
+     * The first name of the account holder.
+     * [Optional]
+     */
+    private String firstName;
+
+    /**
+     * The last name of the account holder.
+     * [Optional]
+     */
+    private String lastName;
+
+    /**
+     * The legal name of a registered company that holds the account.
+     * [Optional]
+     */
+    private String companyName;
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/sepa/SepaAccountHolderType.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/sepa/SepaAccountHolderType.java
new file mode 100644
index 00000000..507e1764
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/sepa/SepaAccountHolderType.java
@@ -0,0 +1,15 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.sepa;
+
+import com.google.gson.annotations.SerializedName;
+
+/**
+ * The type of SEPA account holder.
+ */
+public enum SepaAccountHolderType {
+
+    @SerializedName("individual")
+    INDIVIDUAL,
+
+    @SerializedName("corporate")
+    CORPORATE
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/sepa/SepaMandate.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/sepa/SepaMandate.java
new file mode 100644
index 00000000..1a91574a
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/sepa/SepaMandate.java
@@ -0,0 +1,37 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.sepa;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+import java.time.LocalDate;
+
+/**
+ * The SEPA mandate details.
+ */
+@Data
+@Builder
+@NoArgsConstructor
+@AllArgsConstructor
+public final class SepaMandate {
+
+    /**
+     * The ID of the mandate.
+     * [Optional]
+     */
+    private String id;
+
+    /**
+     * The type of mandate.
+     * [Optional]
+     */
+    private SepaMandateType type;
+
+    /**
+     * The date the mandate was signed.
+     * [Optional]
+     * Format: yyyy-MM-dd
+     */
+    private LocalDate dateOfSignature;
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/sepa/SepaMandateType.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/sepa/SepaMandateType.java
new file mode 100644
index 00000000..8fca68d6
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/sepa/SepaMandateType.java
@@ -0,0 +1,15 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.sepa;
+
+import com.google.gson.annotations.SerializedName;
+
+/**
+ * The type of SEPA mandate.
+ */
+public enum SepaMandateType {
+
+    @SerializedName("core")
+    CORE,
+
+    @SerializedName("b2b")
+    B2B
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/sequra/Sequra.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/sequra/Sequra.java
new file mode 100644
index 00000000..e45d0b03
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/sequra/Sequra.java
@@ -0,0 +1,13 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.sequra;
+
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.PaymentMethodBase;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+/**
+ * The Sequra payment method's details and configuration.
+ */
+@Data
+@EqualsAndHashCode(callSuper = true)
+public final class Sequra extends PaymentMethodBase {
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/stcpay/Stcpay.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/stcpay/Stcpay.java
index bfa232d3..5446286d 100644
--- a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/stcpay/Stcpay.java
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/stcpay/Stcpay.java
@@ -7,7 +7,7 @@
 import lombok.EqualsAndHashCode;
 
 /**
- * STC Pay payment method configuration
+ * STC Pay payment method configuration.
  */
 @Data
 @EqualsAndHashCode(callSuper = true)
@@ -15,19 +15,19 @@ public final class Stcpay extends PaymentMethodBase {
 
     /**
      * The initialization state of the payment method. Defaults to disabled.
-     * <p>[Optional]</p>
+     * [Optional]
      */
     private PaymentMethodInitialization initialization = PaymentMethodInitialization.DISABLED;
 
     /**
-     * The one-time password (OTP) for stc pay.
-     * <p>[Write-only]</p>
+     * The one-time password (OTP) for STC Pay. Write-only.
+     * [Optional]
      */
     private String otp;
 
     /**
-     * The next available action. Contains type {@code otp} when an OTP is required.
-     * <p>[Read-only]</p>
+     * The next available action. Contains type otp when an OTP is required.
+     * [Optional]
      */
     private PaymentMethodAction action;
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/swish/Swish.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/swish/Swish.java
new file mode 100644
index 00000000..93061b52
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/swish/Swish.java
@@ -0,0 +1,25 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.swish;
+
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.PaymentMethodBase;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+/**
+ * The Swish payment method's details and configuration.
+ */
+@Data
+@EqualsAndHashCode(callSuper = true)
+public final class Swish extends PaymentMethodBase {
+
+    /**
+     * A description that appears on the customer's billing statement.
+     * [Optional]
+     */
+    private String billingDescriptor;
+
+    /**
+     * The account holder's details.
+     * [Optional]
+     */
+    private SwishAccountHolder accountHolder;
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/swish/SwishAccountHolder.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/swish/SwishAccountHolder.java
new file mode 100644
index 00000000..2acaf06f
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/swish/SwishAccountHolder.java
@@ -0,0 +1,28 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.swish;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+/**
+ * The Swish account holder's details.
+ */
+@Data
+@Builder
+@NoArgsConstructor
+@AllArgsConstructor
+public final class SwishAccountHolder {
+
+    /**
+     * The account holder's first name.
+     * [Optional]
+     */
+    private String firstName;
+
+    /**
+     * The account holder's last name.
+     * [Optional]
+     */
+    private String lastName;
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/tabby/Tabby.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/tabby/Tabby.java
index 18a0e2a2..fe3f5eb6 100644
--- a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/tabby/Tabby.java
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/tabby/Tabby.java
@@ -2,7 +2,6 @@
 
 import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.PaymentMethodBase;
 import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.PaymentMethodInitialization;
-import com.google.gson.annotations.SerializedName;
 import lombok.Data;
 import lombok.EqualsAndHashCode;
 
@@ -17,14 +16,13 @@ public final class Tabby extends PaymentMethodBase {
 
     /**
      * The initialization state of the payment method. Defaults to disabled.
-     * <p>[Optional]</p>
+     * [Optional]
      */
     private PaymentMethodInitialization initialization = PaymentMethodInitialization.DISABLED;
 
     /**
-     * The available payment types for Tabby (for example, {@code installments}).
-     * <p>[Read-only]</p>
+     * The available payment types for Tabby (for example, installments).
+     * [Optional]
      */
-    @SerializedName("payment_types")
     private List<String> paymentTypes;
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/tamara/Tamara.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/tamara/Tamara.java
new file mode 100644
index 00000000..93304016
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/tamara/Tamara.java
@@ -0,0 +1,13 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.tamara;
+
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.PaymentMethodBase;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+/**
+ * The Tamara payment method's details and configuration.
+ */
+@Data
+@EqualsAndHashCode(callSuper = true)
+public final class Tamara extends PaymentMethodBase {
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/tng/Tng.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/tng/Tng.java
new file mode 100644
index 00000000..b213d398
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/tng/Tng.java
@@ -0,0 +1,29 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.tng;
+
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.OsType;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.PaymentMethodBase;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.TerminalType;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+/**
+ * The TNG payment method's details and configuration.
+ */
+@Data
+@EqualsAndHashCode(callSuper = true)
+public final class Tng extends PaymentMethodBase {
+
+    /**
+     * The client-side terminal type.
+     * [Optional]
+     * Enum: "APP" "WAP" "WEB"
+     */
+    private TerminalType terminalType;
+
+    /**
+     * The customer's operating system type. Required when terminal_type is not WEB.
+     * [Optional]
+     * Enum: "ANDROID" "IOS"
+     */
+    private OsType osType;
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/truemoney/TrueMoney.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/truemoney/TrueMoney.java
new file mode 100644
index 00000000..8b89c7f3
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/truemoney/TrueMoney.java
@@ -0,0 +1,29 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.truemoney;
+
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.OsType;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.PaymentMethodBase;
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.TerminalType;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+/**
+ * The TrueMoney payment method's details and configuration.
+ */
+@Data
+@EqualsAndHashCode(callSuper = true)
+public final class TrueMoney extends PaymentMethodBase {
+
+    /**
+     * The client-side terminal type.
+     * [Optional]
+     * Enum: "APP" "WAP" "WEB"
+     */
+    private TerminalType terminalType;
+
+    /**
+     * The customer's operating system type. Required when terminal_type is not WEB.
+     * [Optional]
+     * Enum: "ANDROID" "IOS"
+     */
+    private OsType osType;
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/twint/Twint.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/twint/Twint.java
new file mode 100644
index 00000000..593035e8
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/twint/Twint.java
@@ -0,0 +1,13 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.twint;
+
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.PaymentMethodBase;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+/**
+ * The Twint payment method's details and configuration.
+ */
+@Data
+@EqualsAndHashCode(callSuper = true)
+public final class Twint extends PaymentMethodBase {
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/vipps/Vipps.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/vipps/Vipps.java
new file mode 100644
index 00000000..83eef920
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/vipps/Vipps.java
@@ -0,0 +1,13 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.vipps;
+
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.PaymentMethodBase;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+/**
+ * The Vipps payment method's details and configuration.
+ */
+@Data
+@EqualsAndHashCode(callSuper = true)
+public final class Vipps extends PaymentMethodBase {
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/wechatpay/WeChatPay.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/wechatpay/WeChatPay.java
new file mode 100644
index 00000000..461cb5ef
--- /dev/null
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/entities/paymentMethods/wechatpay/WeChatPay.java
@@ -0,0 +1,13 @@
+package com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.wechatpay;
+
+import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.common.PaymentMethodBase;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+/**
+ * The WeChatPay payment method's details and configuration.
+ */
+@Data
+@EqualsAndHashCode(callSuper = true)
+public final class WeChatPay extends PaymentMethodBase {
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/requests/PaymentSetupsRequest.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/requests/PaymentSetupsRequest.java
index 2f04f741..4676f78d 100644
--- a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/requests/PaymentSetupsRequest.java
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/requests/PaymentSetupsRequest.java
@@ -2,12 +2,12 @@
 
 import com.checkout.common.Currency;
 import com.checkout.payments.PaymentType;
+import com.checkout.handlepaymentsandpayouts.setups.entities.billing.PaymentSetupBilling;
 import com.checkout.handlepaymentsandpayouts.setups.entities.customer.Customer;
 import com.checkout.handlepaymentsandpayouts.setups.entities.industry.Industry;
 import com.checkout.handlepaymentsandpayouts.setups.entities.order.Order;
 import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.PaymentMethods;
 import com.checkout.handlepaymentsandpayouts.setups.entities.settings.Settings;
-import com.google.gson.annotations.SerializedName;
 import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Data;
@@ -23,10 +23,10 @@
 public final class PaymentSetupsRequest {
 
     /**
-     * The processing channel to be used for the payment setup
+     * The processing channel to be used for the payment setup.
      * [Required]
+     * Pattern: ^(pc)_(\w{26})$
      */
-    @SerializedName("processing_channel_id")
     private String processingChannelId;
 
     /**
@@ -42,10 +42,10 @@ public final class PaymentSetupsRequest {
     private Currency currency;
 
     /**
-     * The type of payment.
-     //// You must provide this field for card payments in which the cardholder is not present. For example, if the transaction is a recurring payment, or a mail order/telephone order (MOTO) payment.
-     * Enum: "Regular" "Recurring" "MOTO" "Installment" "Unscheduled"
+     * The type of payment. Required for card payments where the cardholder is not present,
+     * such as recurring or MOTO payments.
      * [Optional]
+     * Enum: "Regular" "Recurring" "MOTO" "Installment" "PayLater" "Unscheduled"
      */
     @Builder.Default
     private PaymentType paymentType = PaymentType.REGULAR;
@@ -66,7 +66,6 @@ public final class PaymentSetupsRequest {
      * The payment methods that are enabled on your account and available for use
      * [Optional]
      */
-    @SerializedName("payment_methods")
     private PaymentMethods paymentMethods;
 
     /**
@@ -92,4 +91,10 @@ public final class PaymentSetupsRequest {
      * [Optional]
      */
     private Industry industry;
+
+    /**
+     * The billing details for the payment.
+     * [Optional]
+     */
+    private PaymentSetupBilling billing;
 }
\ No newline at end of file
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/responses/PaymentSetupSource.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/responses/PaymentSetupSource.java
index 41a98d92..707f973d 100644
--- a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/responses/PaymentSetupSource.java
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/responses/PaymentSetupSource.java
@@ -11,7 +11,6 @@
 import com.checkout.handlepaymentsandpayouts.payments.common.source.cardsource.AccountUpdateStatusType;
 import com.checkout.handlepaymentsandpayouts.payments.common.source.cardsource.accountholder.AbstractAccountHolder;
 
-import com.google.gson.annotations.SerializedName;
 import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Data;
@@ -27,156 +26,165 @@
 public final class PaymentSetupSource {
 
     /**
-     * The payment source type. sepabank_accountalipay_cnachcardcard
+     * The payment source type.
+     * [Optional]
      */
     private PaymentSourceType type;
 
     /**
-     * The expiry month
+     * The expiry month.
+     * [Optional]
      */
-    @SerializedName("expiry_month")
     private Integer expiryMonth;
 
     /**
-     * The expiry year
+     * The expiry year.
+     * [Optional]
      */
-    @SerializedName("expiry_year")
     private Integer expiryYear;
 
     /**
-     * The last four digits of the card number
+     * The last four digits of the card number.
+     * [Optional]
      */
     private String last4;
 
     /**
      * Uniquely identifies this particular card number. You can use this to compare cards across customers.
+     * [Optional]
      */
     private String fingerprint;
 
     /**
-     * The card issuer's Bank Identification Number (BIN)
+     * The card issuer's Bank Identification Number (BIN).
+     * [Optional]
      */
     private String bin;
 
     /**
-     * The payment source identifier that can be used for subsequent payments. For new sources, this will only be returned if the payment was approved
+     * The payment source identifier that can be used for subsequent payments.
+     * For new sources, this will only be returned if the payment was approved.
+     * [Optional]
      */
     private String id;
 
     /**
-     * The payment source owner's billing address
+     * The payment source owner's billing address.
+     * [Optional]
      */
-    @SerializedName("billing_address")
     private Address billingAddress;
 
     /**
-     * The payment source owner's phone number
+     * The payment source owner's phone number.
+     * [Optional]
      */
     private Phone phone;
 
     /**
-     * The cardholder's name
+     * The cardholder's name.
+     * [Optional]
      */
     private String name;
 
     /**
-     * The card scheme
+     * The card scheme.
+     * [Optional]
      */
     private String scheme;
 
     /**
-     * Deprecated Replaced by local_schemes
-     * The local co-branded card scheme.
+     * Deprecated. Replaced by local_schemes. The local co-branded card scheme.
+     * [Optional]
      */
-    @SerializedName("scheme_local")
     private String schemeLocal;
 
     /**
      * The local co-branded card schemes.
+     * [Optional]
      */
-    @SerializedName("local_schemes")
     private List<String> localSchemes;
 
     /**
-     * The card type
+     * The card type.
+     * [Optional]
      */
-    @SerializedName("card_type")
     private CardType cardType;
 
     /**
-     * The card category
+     * The card category.
+     * [Optional]
      */
-    @SerializedName("card_category")
     private CardCategoryType cardCategory;
 
     /**
-     * The card wallet type
+     * The card wallet type.
+     * [Optional]
      */
-    @SerializedName("card_wallet_type")
     private CardWalletType cardWalletType;
 
     /**
-     * The name of the card issuer
+     * The name of the card issuer.
+     * [Optional]
      */
     private String issuer;
 
     /**
-     * The card issuer's country (two-letter ISO code)
+     * The card issuer's country (two-letter ISO code).
+     * [Optional]
      */
-    @SerializedName("issuer_country")
     private String issuerCountry;
 
     /**
-     * The issuer/card scheme product identifier
+     * The issuer/card scheme product identifier.
+     * [Optional]
      */
-    @SerializedName("product_id")
     private String productId;
 
     /**
-     * The issuer/card scheme product type
+     * The issuer/card scheme product type.
+     * [Optional]
      */
-    @SerializedName("product_type")
     private String productType;
 
     /**
-     * The Address Verification System check result
+     * The Address Verification System check result.
+     * [Optional]
      */
-    @SerializedName("avs_check")
     private String avsCheck;
 
     /**
-     * The card verification value (CVV) check result
+     * The card verification value (CVV) check result.
+     * [Optional]
      */
-    @SerializedName("cvv_check")
     private String cvvCheck;
 
     /**
-     * A unique reference to the underlying card for network tokens (e.g., Apple Pay, Google Pay)
+     * A unique reference to the underlying card for network tokens (e.g., Apple Pay, Google Pay).
+     * [Optional]
      */
-    @SerializedName("payment_account_reference")
     private String paymentAccountReference;
 
     /**
      * The JWE encrypted full card number that has been updated by real-time account updater.
+     * [Optional]
      */
-    @SerializedName("encrypted_card_number")
     private String encryptedCardNumber;
 
     /**
      * Specifies what card information was updated by the Real-Time Account Updater.
+     * [Optional]
      */
-    @SerializedName("account_update_status")
     private AccountUpdateStatusType accountUpdateStatus;
 
     /**
      * Provides the failure code if the Real-Time Account Updater fails to update the card information.
+     * [Optional]
      */
-    @SerializedName("account_update_failure_code")
     private String accountUpdateFailureCode;
 
     /**
-     * Information about the account holder of the card
+     * Information about the account holder of the card.
+     * [Optional]
      */
-    @SerializedName("account_holder")
     private AbstractAccountHolder accountHolder;
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/responses/PaymentSetupsConfirmResponse.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/responses/PaymentSetupsConfirmResponse.java
index 537c0806..dcd31577 100644
--- a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/responses/PaymentSetupsConfirmResponse.java
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/responses/PaymentSetupsConfirmResponse.java
@@ -29,127 +29,144 @@
 public final class PaymentSetupsConfirmResponse extends Resource {
 
     /**
-     * The payment's unique identifier
+     * The payment's unique identifier.
+     * [Optional]
      */
     private String id;
 
     /**
-     * The unique identifier for the action performed against this payment
+     * The unique identifier for the action performed against this payment.
+     * [Optional]
      */
-    @SerializedName("action_id")
     private String actionId;
 
     /**
-     * The payment amount
+     * The payment amount.
+     * [Optional]
      */
     private Long amount;
 
     /**
-     * The three-letter ISO currency code of the payment
+     * The three-letter ISO currency code of the payment.
+     * [Optional]
      */
     private Currency currency;
 
     /**
-     * Whether or not the authorization or capture was successful
+     * Whether or not the authorization or capture was successful.
+     * [Optional]
      */
     private Boolean approved;
 
     /**
-     * The status of the payment
+     * The status of the payment.
+     * [Optional]
      */
     private PaymentStatus status;
 
     /**
-     * The Gateway response code
+     * The Gateway response code.
+     * [Optional]
      */
-    @SerializedName("response_code")
     private String responseCode;
 
     /**
-     * The date and time at which the payment was processed
+     * The date and time at which the payment was processed.
+     * [Optional]
+     * Format: date-time (ISO 8601)
      */
-    @SerializedName("processed_on")
     private Instant processedOn;
 
     /**
-     * The full amount from the original authorization, if a partial authorization was requested and approved
+     * The full amount from the original authorization, if a partial authorization was requested and approved.
+     * [Optional]
      */
-    @SerializedName("amount_requested")
     private Long amountRequested;
 
     /**
-     * The acquirer authorization code if the payment was authorized
+     * The acquirer authorization code if the payment was authorized.
+     * [Optional]
      */
-    @SerializedName("auth_code")
     private String authCode;
 
     /**
-     * The Gateway response summary
+     * The Gateway response summary.
+     * [Optional]
      */
-    @SerializedName("response_summary")
     private String responseSummary;
 
     /**
-     * The timestamp (ISO 8601 code) for when the authorization's validity period expires
+     * The timestamp for when the authorization's validity period expires.
+     * [Optional]
+     * Format: date-time (ISO 8601)
      */
-    @SerializedName("expires_on")
     private String expiresOn;
 
     /**
-     * Provides 3D Secure enrollment status if the payment was downgraded to non-3D Secure
+     * Provides 3D Secure enrollment status if the payment was downgraded to non-3D Secure.
+     * [Optional]
      */
     @SerializedName("3ds")
     private Threeds threeDSecure;
 
     /**
-     * Returns the payment's risk assessment results
+     * Returns the payment's risk assessment results.
+     * [Optional]
      */
     private Risk risk;
 
     /**
-     * The source of the payment
+     * The source of the payment.
+     * [Optional]
      */
     private PaymentSetupSource source;
 
     /**
-     * The customer associated with the payment, if provided in the request
+     * The customer associated with the payment, if provided in the request.
+     * [Optional]
      */
     private Customer customer;
 
     /**
-     * The payment balances
+     * The payment balances.
+     * [Optional]
      */
     private Balances balances;
 
     /**
-     * Your reference for the payment
+     * Your reference for the payment.
+     * [Optional]
      */
     private String reference;
 
     /**
-     * The The details of the subscription
+     * The details of the subscription.
+     * [Optional]
      */
     private Subscription subscription;
 
     /**
-     * Returns information related to the processing of the payment
+     * Returns information related to the processing of the payment.
+     * [Optional]
      */
     private Processing processing;
 
     /**
-     *  The final Electronic Commerce Indicator (ECI) security level used to authorize the payment. 
-     *  Applicable for 3D Secure and network token payments
+     * The final Electronic Commerce Indicator (ECI) security level used to authorize the payment.
+     * Applicable for 3D Secure and network token payments.
+     * [Optional]
      */
     private String eci;
 
     /**
-     * The scheme transaction identifier
+     * The scheme transaction identifier.
+     * [Optional]
      */
-    @SerializedName("scheme_id")
     private String schemeId;
 
     /**
-     * The retry information
+     * The retry information.
+     * [Optional]
      */
     private Retry retry;
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/responses/PaymentSetupsResponse.java b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/responses/PaymentSetupsResponse.java
index c1172806..868b8b9c 100644
--- a/src/main/java/com/checkout/handlepaymentsandpayouts/setups/responses/PaymentSetupsResponse.java
+++ b/src/main/java/com/checkout/handlepaymentsandpayouts/setups/responses/PaymentSetupsResponse.java
@@ -2,12 +2,15 @@
 
 import com.checkout.common.Resource;
 import com.checkout.common.Currency;
+import com.checkout.handlepaymentsandpayouts.setups.entities.billing.PaymentSetupBilling;
 import com.checkout.handlepaymentsandpayouts.setups.entities.customer.Customer;
 import com.checkout.handlepaymentsandpayouts.setups.entities.industry.Industry;
 import com.checkout.handlepaymentsandpayouts.setups.entities.order.Order;
 import com.checkout.handlepaymentsandpayouts.setups.entities.paymentMethods.PaymentMethods;
 import com.checkout.handlepaymentsandpayouts.setups.entities.settings.Settings;
 import com.checkout.payments.PaymentType;
+
+import java.util.List;
 import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Data;
@@ -26,61 +29,88 @@ public final class PaymentSetupsResponse extends Resource {
 
     /**
      * The unique identifier of the payment setup.
+     * [Optional]
      */
     private String id;
 
     /**
-     * The processing channel used for the payment setup
+     * The processing channel used for the payment setup.
+     * [Required]
+     * Pattern: ^(pc)_(\w{26})$
      */
     private String processingChannelId;
 
     /**
-     * The payment amount. The exact format depends on the currency
+     * The payment amount in the minor currency unit.
+     * [Required]
      */
     private Long amount;
 
     /**
-     * The three-letter ISO currency code
+     * The three-letter ISO currency code.
+     * [Required]
      */
     private Currency currency;
 
     /**
-     * The type of payment method
+     * The type of payment.
+     * [Optional]
+     * Enum: "Regular" "Recurring" "MOTO" "Installment" "PayLater" "Unscheduled"
      */
     private PaymentType paymentType;
 
     /**
-     * The reference identifier for this payment setup
+     * A reference you can use to identify the payment setup, such as an order number.
+     * [Optional]
      */
     private String reference;
 
     /**
-     * A description of the payment setup
+     * A description of the payment setup.
+     * [Optional]
      */
     private String description;
 
     /**
-     * The payment method configuration for this setup
+     * The payment method configuration for this setup.
+     * [Optional]
      */
     private PaymentMethods paymentMethods;
 
     /**
-     * The payment setup configuration settings
+     * The payment setup configuration settings.
+     * [Optional]
      */
     private Settings settings;
 
     /**
-     * Details about the customer
+     * Details about the customer.
+     * [Optional]
      */
     private Customer customer;
 
     /**
-     * Details about the order associated with this payment setup
+     * Details about the order associated with this payment setup.
+     * [Optional]
      */
     private Order order;
 
     /**
-     * Industry-specific information for specialized payment scenarios
+     * Industry-specific information for specialized payment scenarios.
+     * [Optional]
      */
     private Industry industry;
-}
\ No newline at end of file
+
+    /**
+     * The billing details for the payment.
+     * [Optional]
+     */
+    private PaymentSetupBilling billing;
+
+    /**
+     * An ordered list of available payment method names. The order indicates the recommended
+     * presentation priority, with the first item being the highest priority.
+     * [Optional]
+     */
+    private List<String> availablePaymentMethods;
+}
diff --git a/src/main/java/com/checkout/instruments/create/CreateInstrumentSepaRequest.java b/src/main/java/com/checkout/instruments/create/CreateInstrumentSepaRequest.java
index a7fb7340..b8811d86 100644
--- a/src/main/java/com/checkout/instruments/create/CreateInstrumentSepaRequest.java
+++ b/src/main/java/com/checkout/instruments/create/CreateInstrumentSepaRequest.java
@@ -1,9 +1,7 @@
 package com.checkout.instruments.create;
 
 import com.checkout.common.AccountHolder;
-import com.checkout.common.AccountType;
 import com.checkout.common.InstrumentType;
-import com.google.gson.annotations.SerializedName;
 import lombok.Builder;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
@@ -16,18 +14,32 @@
 @ToString(callSuper = true)
 public final class CreateInstrumentSepaRequest extends CreateInstrumentRequest {
 
-    @SerializedName("instrument_data")
+    /**
+     * The details of the SEPA mandate, including IBAN, country, currency, payment type, and mandate ID.
+     * [Required]
+     */
     private InstrumentData instrumentData;
 
-    @SerializedName("account_holder")
+    /**
+     * The account holder details. Must include first_name, last_name, and billing_address.
+     * [Required]
+     */
     private AccountHolder accountHolder;
 
+    /**
+     * The customer details. Associates the instrument with an existing or new customer.
+     * [Optional]
+     */
+    private CreateCustomerInstrumentRequest customer;
+
     @Builder
     private CreateInstrumentSepaRequest(final InstrumentData instrumentData,
-                                        final AccountHolder accountHolder) {
+                                        final AccountHolder accountHolder,
+                                        final CreateCustomerInstrumentRequest customer) {
         super(InstrumentType.SEPA);
         this.instrumentData = instrumentData;
         this.accountHolder = accountHolder;
+        this.customer = customer;
     }
 
     public CreateInstrumentSepaRequest() {
diff --git a/src/main/java/com/checkout/instruments/get/GetCardInstrumentResponse.java b/src/main/java/com/checkout/instruments/get/GetCardInstrumentResponse.java
index 46a53bd3..c4e2f944 100644
--- a/src/main/java/com/checkout/instruments/get/GetCardInstrumentResponse.java
+++ b/src/main/java/com/checkout/instruments/get/GetCardInstrumentResponse.java
@@ -2,9 +2,9 @@
 
 import com.checkout.common.CardCategory;
 import com.checkout.common.CardType;
+import com.checkout.common.CardWalletType;
 import com.checkout.common.CountryCode;
 import com.checkout.common.InstrumentType;
-import com.google.gson.annotations.SerializedName;
 import lombok.Data;
 import lombok.EqualsAndHashCode;
 import lombok.ToString;
@@ -16,38 +16,107 @@ public final class GetCardInstrumentResponse extends GetInstrumentResponse {
 
     private final InstrumentType type = InstrumentType.CARD;
 
-    @SerializedName("expiry_month")
+    /**
+     * The expiry month of the card.
+     * [Optional]
+     */
     private Integer expiryMonth;
 
-    @SerializedName("expiry_year")
+    /**
+     * The expiry year of the card.
+     * [Optional]
+     */
     private Integer expiryYear;
 
+    /**
+     * The name of the cardholder.
+     * [Optional]
+     */
     private String name;
 
+    /**
+     * The card scheme.
+     * [Optional]
+     */
     private String scheme;
 
-    @SerializedName("scheme_local")
+    /**
+     * The local card scheme.
+     * [Optional]
+     */
     private String schemeLocal;
 
+    /**
+     * The last four digits of the card number.
+     * [Optional]
+     */
     private String last4;
 
+    /**
+     * The card BIN (Bank Identification Number).
+     * [Optional]
+     */
     private String bin;
 
-    @SerializedName("card_type")
+    /**
+     * The card type.
+     * [Optional]
+     */
     private CardType cardType;
 
-    @SerializedName("card_category")
+    /**
+     * The card category.
+     * [Optional]
+     */
     private CardCategory cardCategory;
 
+    /**
+     * The name of the card issuer.
+     * [Optional]
+     */
     private String issuer;
 
-    @SerializedName("issuer_country")
+    /**
+     * The country of the card issuer.
+     * [Optional]
+     */
     private CountryCode issuerCountry;
 
-    @SerializedName("product_id")
+    /**
+     * The card product identifier.
+     * [Optional]
+     */
     private String productId;
 
-    @SerializedName("product_type")
+    /**
+     * The card product type.
+     * [Optional]
+     */
     private String productType;
 
+    /**
+     * The JWE-encrypted full card number. This is only present if your level of PCI compliance is SAQ-D.
+     * [Optional]
+     */
+    private String encryptedCardNumber;
+
+    /**
+     * The network token associated with this instrument.
+     * [Optional]
+     */
+    private InstrumentNetworkToken networkToken;
+
+    /**
+     * The card wallet type used for this instrument.
+     * [Optional]
+     * Enum: "googlepay" "applepay"
+     */
+    private CardWalletType cardWalletType;
+
+    /**
+     * Indicates whether the card is subject to interchange regulation.
+     * [Required]
+     */
+    private Boolean regulatedIndicator;
+
 }
diff --git a/src/main/java/com/checkout/instruments/get/InstrumentNetworkToken.java b/src/main/java/com/checkout/instruments/get/InstrumentNetworkToken.java
new file mode 100644
index 00000000..740fccc5
--- /dev/null
+++ b/src/main/java/com/checkout/instruments/get/InstrumentNetworkToken.java
@@ -0,0 +1,22 @@
+package com.checkout.instruments.get;
+
+import lombok.Data;
+
+@Data
+public final class InstrumentNetworkToken {
+
+    /**
+     * The unique identifier for the network token.
+     * [Optional]
+     * Pattern: ^(nt)_(\w{26})$
+     */
+    private String id;
+
+    /**
+     * The state of the network token.
+     * [Optional]
+     * Enum: "active" "suspended" "inactive"
+     */
+    private NetworkTokenState state;
+
+}
diff --git a/src/main/java/com/checkout/instruments/get/NetworkTokenState.java b/src/main/java/com/checkout/instruments/get/NetworkTokenState.java
new file mode 100644
index 00000000..5871e9bd
--- /dev/null
+++ b/src/main/java/com/checkout/instruments/get/NetworkTokenState.java
@@ -0,0 +1,16 @@
+package com.checkout.instruments.get;
+
+import com.google.gson.annotations.SerializedName;
+
+public enum NetworkTokenState {
+
+    @SerializedName("active")
+    ACTIVE,
+
+    @SerializedName("suspended")
+    SUSPENDED,
+
+    @SerializedName("inactive")
+    INACTIVE,
+
+}
diff --git a/src/main/java/com/checkout/instruments/update/AchInstrumentAccountType.java b/src/main/java/com/checkout/instruments/update/AchInstrumentAccountType.java
new file mode 100644
index 00000000..d52c76e9
--- /dev/null
+++ b/src/main/java/com/checkout/instruments/update/AchInstrumentAccountType.java
@@ -0,0 +1,13 @@
+package com.checkout.instruments.update;
+
+import com.google.gson.annotations.SerializedName;
+
+public enum AchInstrumentAccountType {
+
+    @SerializedName("savings")
+    SAVINGS,
+
+    @SerializedName("checking")
+    CHECKING
+
+}
diff --git a/src/main/java/com/checkout/instruments/update/SepaPaymentType.java b/src/main/java/com/checkout/instruments/update/SepaPaymentType.java
new file mode 100644
index 00000000..97b55fd6
--- /dev/null
+++ b/src/main/java/com/checkout/instruments/update/SepaPaymentType.java
@@ -0,0 +1,13 @@
+package com.checkout.instruments.update;
+
+import com.google.gson.annotations.SerializedName;
+
+public enum SepaPaymentType {
+
+    @SerializedName("recurring")
+    RECURRING,
+
+    @SerializedName("regular")
+    REGULAR
+
+}
diff --git a/src/main/java/com/checkout/instruments/update/UpdateInstrumentAchRequest.java b/src/main/java/com/checkout/instruments/update/UpdateInstrumentAchRequest.java
new file mode 100644
index 00000000..d9f2148b
--- /dev/null
+++ b/src/main/java/com/checkout/instruments/update/UpdateInstrumentAchRequest.java
@@ -0,0 +1,56 @@
+package com.checkout.instruments.update;
+
+import com.checkout.common.AccountHolder;
+import com.checkout.common.CountryCode;
+import com.checkout.common.Currency;
+import com.checkout.common.InstrumentType;
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+import lombok.ToString;
+
+@Getter
+@Setter
+@EqualsAndHashCode(callSuper = true)
+@ToString(callSuper = true)
+public final class UpdateInstrumentAchRequest extends UpdateInstrumentRequest {
+
+    private AchInstrumentData instrumentData;
+
+    private AccountHolder accountHolder;
+
+    @Builder
+    private UpdateInstrumentAchRequest(final AchInstrumentData instrumentData,
+                                       final AccountHolder accountHolder) {
+        super(InstrumentType.ACH);
+        this.instrumentData = instrumentData;
+        this.accountHolder = accountHolder;
+    }
+
+    public UpdateInstrumentAchRequest() {
+        super(InstrumentType.ACH);
+    }
+
+    @Data
+    @Builder
+    @NoArgsConstructor
+    @AllArgsConstructor
+    public static final class AchInstrumentData {
+
+        private AchInstrumentAccountType accountType;
+
+        private String accountNumber;
+
+        private String bankCode;
+
+        private Currency currency;
+
+        private CountryCode country;
+
+    }
+
+}
diff --git a/src/main/java/com/checkout/instruments/update/UpdateInstrumentAchResponse.java b/src/main/java/com/checkout/instruments/update/UpdateInstrumentAchResponse.java
new file mode 100644
index 00000000..cb825724
--- /dev/null
+++ b/src/main/java/com/checkout/instruments/update/UpdateInstrumentAchResponse.java
@@ -0,0 +1,15 @@
+package com.checkout.instruments.update;
+
+import com.checkout.common.InstrumentType;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+import lombok.ToString;
+
+@Data
+@EqualsAndHashCode(callSuper = true)
+@ToString(callSuper = true)
+public final class UpdateInstrumentAchResponse extends UpdateInstrumentResponse {
+
+    private final InstrumentType type = InstrumentType.ACH;
+
+}
diff --git a/src/main/java/com/checkout/instruments/update/UpdateInstrumentSepaRequest.java b/src/main/java/com/checkout/instruments/update/UpdateInstrumentSepaRequest.java
new file mode 100644
index 00000000..a3ac4c47
--- /dev/null
+++ b/src/main/java/com/checkout/instruments/update/UpdateInstrumentSepaRequest.java
@@ -0,0 +1,100 @@
+package com.checkout.instruments.update;
+
+import com.checkout.common.AccountHolder;
+import com.checkout.common.CountryCode;
+import com.checkout.common.Currency;
+import com.checkout.common.InstrumentType;
+import com.checkout.payments.request.source.apm.MandateType;
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+import lombok.ToString;
+
+import java.time.LocalDate;
+
+@Getter
+@Setter
+@EqualsAndHashCode(callSuper = true)
+@ToString(callSuper = true)
+public final class UpdateInstrumentSepaRequest extends UpdateInstrumentRequest {
+
+    /**
+     * SEPA-specific instrument data to update.
+     * [Optional]
+     */
+    private SepaInstrumentData instrumentData;
+
+    /**
+     * The account holder details.
+     * [Optional]
+     */
+    private AccountHolder accountHolder;
+
+    @Builder
+    private UpdateInstrumentSepaRequest(final SepaInstrumentData instrumentData,
+                                        final AccountHolder accountHolder) {
+        super(InstrumentType.SEPA);
+        this.instrumentData = instrumentData;
+        this.accountHolder = accountHolder;
+    }
+
+    public UpdateInstrumentSepaRequest() {
+        super(InstrumentType.SEPA);
+    }
+
+    @Data
+    @Builder
+    @NoArgsConstructor
+    @AllArgsConstructor
+    public static final class SepaInstrumentData {
+
+        /**
+         * The SEPA mandate type.
+         * [Optional]
+         */
+        private MandateType type;
+
+        /**
+         * The IBAN account number.
+         * [Optional]
+         */
+        private String accountNumber;
+
+        /**
+         * The two-letter ISO country code.
+         * [Optional]
+         */
+        private CountryCode country;
+
+        /**
+         * The three-letter ISO currency code.
+         * [Optional]
+         */
+        private Currency currency;
+
+        /**
+         * The SEPA payment type.
+         * [Optional]
+         */
+        private SepaPaymentType paymentType;
+
+        /**
+         * The SEPA mandate identifier.
+         * [Optional]
+         */
+        private String mandateId;
+
+        /**
+         * The date the SEPA mandate was signed.
+         * [Optional]
+         * Format: yyyy-MM-dd
+         */
+        private LocalDate dateOfSignature;
+
+    }
+
+}
diff --git a/src/main/java/com/checkout/instruments/update/UpdateInstrumentSepaResponse.java b/src/main/java/com/checkout/instruments/update/UpdateInstrumentSepaResponse.java
new file mode 100644
index 00000000..87f43378
--- /dev/null
+++ b/src/main/java/com/checkout/instruments/update/UpdateInstrumentSepaResponse.java
@@ -0,0 +1,15 @@
+package com.checkout.instruments.update;
+
+import com.checkout.common.InstrumentType;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+import lombok.ToString;
+
+@Data
+@EqualsAndHashCode(callSuper = true)
+@ToString(callSuper = true)
+public final class UpdateInstrumentSepaResponse extends UpdateInstrumentResponse {
+
+    private final InstrumentType type = InstrumentType.SEPA;
+
+}
diff --git a/src/main/java/com/checkout/issuing/cards/requests/create/ShippingInstruction.java b/src/main/java/com/checkout/issuing/cards/requests/create/ShippingInstruction.java
index ec003f8c..c7f33af9 100644
--- a/src/main/java/com/checkout/issuing/cards/requests/create/ShippingInstruction.java
+++ b/src/main/java/com/checkout/issuing/cards/requests/create/ShippingInstruction.java
@@ -1,7 +1,6 @@
 package com.checkout.issuing.cards.requests.create;
 
 import com.checkout.common.Address;
-import com.google.gson.annotations.SerializedName;
 import lombok.Builder;
 import lombok.Data;
 
@@ -9,12 +8,25 @@
 @Builder
 public final class ShippingInstruction {
 
-    @SerializedName("shipping_recipient")
+    /**
+     * The name of the person the card will be shipped to.
+     * [Optional]
+     * @deprecated No longer supported.
+     */
+    @Deprecated
     private String shippingRecipient;
 
-    @SerializedName("shipping_address")
+    /**
+     * The address to ship the physical card to.
+     * [Optional]
+     */
     private Address shippingAddress;
 
-    @SerializedName("additional_comment")
+    /**
+     * Any additional comment on shipping.
+     * [Optional]
+     * @deprecated No longer supported.
+     */
+    @Deprecated
     private String additionalComment;
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/checkout/payments/AccommodationData.java b/src/main/java/com/checkout/payments/AccommodationData.java
new file mode 100644
index 00000000..d540a746
--- /dev/null
+++ b/src/main/java/com/checkout/payments/AccommodationData.java
@@ -0,0 +1,100 @@
+package com.checkout.payments;
+
+import com.checkout.common.Address;
+import com.checkout.common.CountryCode;
+import com.checkout.common.Phone;
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+import java.time.LocalDate;
+import java.util.List;
+
+@Data
+@Builder
+@NoArgsConstructor
+@AllArgsConstructor
+public final class AccommodationData {
+
+    /**
+     * The name of the accommodation property.
+     * [Optional]
+     */
+    private String name;
+
+    /**
+     * The booking reference for this accommodation.
+     * [Optional]
+     */
+    private String bookingReference;
+
+    /**
+     * The check-in date.
+     * [Optional]
+     * Format: date (yyyy-MM-dd)
+     */
+    private LocalDate checkInDate;
+
+    /**
+     * The check-out date.
+     * [Optional]
+     * Format: date (yyyy-MM-dd)
+     */
+    private LocalDate checkOutDate;
+
+    /**
+     * The address of the accommodation property.
+     * [Optional]
+     */
+    private Address address;
+
+    /**
+     * The state or region code where the property is located, as an ISO 3166-2 subdivision code.
+     * [Optional]
+     */
+    private String state;
+
+    /**
+     * The country where the property is located, as an ISO 3166-1 alpha-2 code.
+     * [Optional]
+     */
+    private CountryCode country;
+
+    /**
+     * The city where the property is located.
+     * [Optional]
+     */
+    private String city;
+
+    /**
+     * The number of rooms booked.
+     * [Optional]
+     */
+    private Integer numberOfRooms;
+
+    /**
+     * The list of guests for this booking.
+     * [Optional]
+     */
+    private List<AccommodationGuest> guests;
+
+    /**
+     * The room details for this booking.
+     * [Optional]
+     */
+    private List<AccommodationRoom> room;
+
+    /**
+     * The property's phone numbers.
+     * [Optional]
+     */
+    private List<Phone> propertyPhone;
+
+    /**
+     * The customer service phone numbers for the property.
+     * [Optional]
+     */
+    private List<Phone> customerServicePhone;
+
+}
diff --git a/src/main/java/com/checkout/payments/AccommodationGuest.java b/src/main/java/com/checkout/payments/AccommodationGuest.java
new file mode 100644
index 00000000..3fe37bd1
--- /dev/null
+++ b/src/main/java/com/checkout/payments/AccommodationGuest.java
@@ -0,0 +1,35 @@
+package com.checkout.payments;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+import java.time.LocalDate;
+
+@Data
+@Builder
+@NoArgsConstructor
+@AllArgsConstructor
+public final class AccommodationGuest {
+
+    /**
+     * The guest's first name.
+     * [Optional]
+     */
+    private String firstName;
+
+    /**
+     * The guest's last name.
+     * [Optional]
+     */
+    private String lastName;
+
+    /**
+     * The guest's date of birth.
+     * [Optional]
+     * Format: date (yyyy-MM-dd)
+     */
+    private LocalDate dateOfBirth;
+
+}
diff --git a/src/main/java/com/checkout/payments/AccommodationRoom.java b/src/main/java/com/checkout/payments/AccommodationRoom.java
new file mode 100644
index 00000000..c1b65a45
--- /dev/null
+++ b/src/main/java/com/checkout/payments/AccommodationRoom.java
@@ -0,0 +1,26 @@
+package com.checkout.payments;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+@Data
+@Builder
+@NoArgsConstructor
+@AllArgsConstructor
+public final class AccommodationRoom {
+
+    /**
+     * The room rate amount.
+     * [Optional]
+     */
+    private String rate;
+
+    /**
+     * The number of nights at the specified room rate.
+     * [Optional]
+     */
+    private String numberOfNightsAtRoomRate;
+
+}
diff --git a/src/main/java/com/checkout/payments/AchServiceType.java b/src/main/java/com/checkout/payments/AchServiceType.java
new file mode 100644
index 00000000..162b03a7
--- /dev/null
+++ b/src/main/java/com/checkout/payments/AchServiceType.java
@@ -0,0 +1,13 @@
+package com.checkout.payments;
+
+import com.google.gson.annotations.SerializedName;
+
+public enum AchServiceType {
+
+    @SerializedName("same_day")
+    SAME_DAY,
+
+    @SerializedName("standard")
+    STANDARD
+
+}
diff --git a/src/main/java/com/checkout/payments/Aggregator.java b/src/main/java/com/checkout/payments/Aggregator.java
new file mode 100644
index 00000000..cc188a3e
--- /dev/null
+++ b/src/main/java/com/checkout/payments/Aggregator.java
@@ -0,0 +1,31 @@
+package com.checkout.payments;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+/**
+ * Information about the payment aggregator.
+ */
+@Data
+@Builder
+@NoArgsConstructor
+@AllArgsConstructor
+public final class Aggregator {
+
+    /**
+     * The sub-merchant ID.
+     */
+    private String subMerchantId;
+
+    /**
+     * The Visa identifier for the payment aggregator.
+     */
+    private String aggregatorIdVisa;
+
+    /**
+     * The Mastercard identifier for the payment aggregator.
+     */
+    private String aggregatorIdMc;
+}
diff --git a/src/main/java/com/checkout/payments/PaymentProcessing.java b/src/main/java/com/checkout/payments/PaymentProcessing.java
index 6bf3ed27..d1b0760c 100644
--- a/src/main/java/com/checkout/payments/PaymentProcessing.java
+++ b/src/main/java/com/checkout/payments/PaymentProcessing.java
@@ -1,7 +1,6 @@
 package com.checkout.payments;
 
 import com.checkout.common.CountryCode;
-import com.google.gson.annotations.SerializedName;
 import lombok.Data;
 
 import java.util.List;
@@ -9,91 +8,198 @@
 @Data
 public final class PaymentProcessing {
 
-    @SerializedName("retrieval_reference_number")
+    /**
+     * A unique identifier for the authorization submitted to the card scheme during processing.
+     * [Optional]
+     */
     private String retrievalReferenceNumber;
 
-    @SerializedName("acquirer_transaction_id")
+    /**
+     * A unique identifier for the transaction generated by the acquirer.
+     * [Optional]
+     */
     private String acquirerTransactionId;
 
-    @SerializedName("acquirer_name")
+    /**
+     * The name of the acquirer that processed the payment.
+     * [Optional]
+     */
     private String acquirerName;
 
-    @SerializedName("acquirer_country_code")
+    /**
+     * The two-letter ISO country code of the acquirer country.
+     * [Optional]
+     */
     private CountryCode acquirerCountryCode;
 
-    @SerializedName("recommendation_code")
+    /**
+     * A code representing the recommended follow-up action for the payment, as provided by Checkout.com.
+     * [Optional]
+     */
     private String recommendationCode;
-    
+
+    /**
+     * The scheme the transaction was processed with.
+     * [Optional]
+     */
     private String scheme;
 
-    @SerializedName("partner_merchant_advice_code") 
+    /**
+     * The Merchant Advice Code (MAC) provided by Mastercard with additional transaction information.
+     * [Optional]
+     */
     private String partnerMerchantAdviceCode;
-    
-    @SerializedName("partner_response_code")
+
+    /**
+     * The original authorization response code sent by the scheme (raw response code).
+     * [Optional]
+     */
     private String partnerResponseCode;
 
-    @SerializedName("partner_order_id")
+    /**
+     * Unique order identification of an Afterpay payment.
+     * [Optional]
+     */
     private String partnerOrderId;
 
-    @SerializedName("partner_session_id")
+    /**
+     * The partner session identifier associated with the payment.
+     * [Optional]
+     */
     private String partnerSessionId;
 
-    @SerializedName("partner_client_token")
+    /**
+     * The client token returned by the partner for client-side initialization.
+     * [Optional]
+     */
     private String partnerClientToken;
 
-    @SerializedName("partner_payment_id")
+    /**
+     * Unique identification of a payment provided by partner.
+     * [Optional]
+     */
     private String partnerPaymentId;
 
-    @SerializedName("pan_type_processed")
+    /**
+     * The type of Primary Account Number (PAN) used: fpan (full card) or dpan (network token).
+     * [Optional]
+     * Enum: "fpan" "dpan"
+     */
     private PanProcessedType panTypeProcessed;
 
-    @SerializedName("continuation_payload")
+    /**
+     * A payload used to continue processing for multi-step payment flows.
+     * [Optional]
+     */
     private String continuationPayload;
 
+    /**
+     * The Payment Unique Number (PUN) assigned to the payment.
+     * [Optional]
+     */
     private String pun;
 
-    @SerializedName("partner_status")
+    /**
+     * The status of the payment as reported by the partner.
+     * [Optional]
+     */
     private String partnerStatus;
 
-    @SerializedName("partner_transaction_id")
+    /**
+     * Unique transaction identification provided by partner.
+     * [Optional]
+     */
     private String partnerTransactionId;
 
-    @SerializedName("partner_error_codes")
+    /**
+     * Error codes provided by the partner for a failed or declined payment.
+     * [Optional]
+     */
     private List<String> partnerErrorCodes;
 
-    @SerializedName("partner_error_message")
+    /**
+     * Error description provided by the partner.
+     * [Optional]
+     */
     private String partnerErrorMessage;
 
-    @SerializedName("partner_authorization_code")
+    /**
+     * Authorization code provided by the partner.
+     * [Optional]
+     */
     private String partnerAuthorizationCode;
 
-    @SerializedName("partner_authorization_response_code")
+    /**
+     * Authorization response code provided by the partner.
+     * [Optional]
+     */
     private String partnerAuthorizationResponseCode;
-    
-    @SerializedName("surcharge_amount")
+
+    /**
+     * Surcharge amount applied to the transaction in minor currency units.
+     * [Optional]
+     */
     private Long surchargeAmount;
 
-    @SerializedName("cko_network_token_available")
+    /**
+     * Indicates whether a Checkout.com Network Token was available for the payment.
+     * [Optional]
+     */
     private Boolean ckoNetworkTokenAvailable;
 
-    @SerializedName("purchase_country")
+    /**
+     * The country where the purchase was made. ISO 3166-1 alpha-2 country code.
+     * [Optional]
+     * max 2 characters
+     */
     private CountryCode purchaseCountry;
 
-    @SerializedName("scheme_merchant_id")
+    /**
+     * The merchant identifier configured with the scheme and used for the payment.
+     * [Optional]
+     */
     private String schemeMerchantId;
 
-    @SerializedName("foreign_retailer_amount")
+    /**
+     * The foreign retailer amount applied by the merchant, in minor currency units.
+     * [Optional]
+     */
     private Long foreignRetailerAmount;
 
-    @SerializedName("provision_network_token")
+    /**
+     * Indicates whether a network token should be provisioned for the payment.
+     * [Optional]
+     */
     private Boolean provisionNetworkToken;
 
-    @SerializedName("merchant_category_code")
+    /**
+     * The merchant category code (MCC) associated with the payment.
+     * [Optional]
+     */
     private String merchantCategoryCode;
 
+    /**
+     * Indicates whether this is an Account Funding Transaction (AFT).
+     * [Optional]
+     */
     private Boolean aft;
 
-    @SerializedName("bizum_payment_id")
+    /**
+     * The Bizum payment identifier returned when processing a Bizum payment.
+     * [Optional]
+     */
     private String bizumPaymentId;
 
+    /**
+     * A reconciliation identifier for the payment.
+     * [Optional]
+     */
+    private String reconciliationId;
+
+    /**
+     * The aggregator information for this payment.
+     * [Optional]
+     */
+    private Aggregator aggregator;
+
 }
diff --git a/src/main/java/com/checkout/payments/PaymentRecipient.java b/src/main/java/com/checkout/payments/PaymentRecipient.java
index 8d006a19..ad28c04a 100644
--- a/src/main/java/com/checkout/payments/PaymentRecipient.java
+++ b/src/main/java/com/checkout/payments/PaymentRecipient.java
@@ -9,19 +9,44 @@
 @Builder
 public final class PaymentRecipient {
 
+    /**
+     * The recipient's date of birth.
+     * [Optional]
+     * Format: yyyy-MM-dd
+     */
     @SerializedName("dob")
     private String dateOfBirth;
 
-    @SerializedName("account_number")
+    /**
+     * Any identifier related to the primary recipient's account, such as part of the PAN,
+     * an IBAN, an internal account number, or a phone number.
+     * [Optional]
+     */
     private String accountNumber;
 
+    /**
+     * The recipient's address.
+     * [Optional]
+     */
     private Address address;
 
+    /**
+     * The first part of the UK postcode (e.g., SW1A 1AA would be SW1A). Replaced by address.zip.
+     * [Optional]
+     * @deprecated Use {@code address.zip} instead.
+     */
+    @Deprecated
     private String zip;
 
-    @SerializedName("first_name")
+    /**
+     * The recipient's first name.
+     * [Optional]
+     */
     private String firstName;
 
-    @SerializedName("last_name")
+    /**
+     * The recipient's last name.
+     * [Optional]
+     */
     private String lastName;
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/checkout/payments/ProcessingSettings.java b/src/main/java/com/checkout/payments/ProcessingSettings.java
index d1642032..b3dd84f9 100644
--- a/src/main/java/com/checkout/payments/ProcessingSettings.java
+++ b/src/main/java/com/checkout/payments/ProcessingSettings.java
@@ -4,7 +4,6 @@
 import com.checkout.common.CountryCode;
 import com.checkout.common.ShippingInfo;
 import com.checkout.payments.previous.request.SenderInformation;
-import com.google.gson.annotations.SerializedName;
 import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Data;
@@ -19,116 +18,286 @@
 @AllArgsConstructor
 public final class ProcessingSettings {
 
-    @SerializedName("order_id")
+    /**
+     * The cardholder-provided purchase order or invoice number.
+     * [Optional]
+     * max 15 characters
+     */
     private String orderId;
 
-    @SerializedName("tax_amount")
+    /**
+     * The total amount of sales tax on the total purchase amount.
+     * [Optional]
+     */
     private Long taxAmount;
 
-    @SerializedName("discount_amount")
+    /**
+     * The surcharge amount applied to the transaction in minor currency units by the merchant.
+     * [Optional]
+     */
+    private Long surchargeAmount;
+
+    /**
+     * The discount amount applied to the transaction by the merchant.
+     * [Optional]
+     */
     private Long discountAmount;
 
-    @SerializedName("duty_amount")
+    /**
+     * The total charges for any import or export duty included in the transaction.
+     * [Optional]
+     */
     private Long dutyAmount;
 
-    @SerializedName("shipping_amount")
+    /**
+     * The total freight or shipping and handling charges for the transaction.
+     * [Optional]
+     */
     private Long shippingAmount;
 
-    @SerializedName("shipping_tax_amount")
+    /**
+     * The tax amount on the freight or shipping and handling charges for the transaction.
+     * [Optional]
+     */
     private Long shippingTaxAmount;
 
+    /**
+     * Indicates if the payment is an Account Funding Transaction (AFT).
+     * [Optional]
+     */
     private boolean aft;
 
-    @SerializedName("preferred_scheme")
+    /**
+     * The preferred scheme for co-badged card payment processing.
+     * [Optional]
+     * Enum: "mastercard" "visa" "cartes_bancaires"
+     */
     private PreferredSchema preferredScheme;
 
-    @SerializedName("merchant_initiated_reason")
+    /**
+     * Indicates the reason for a merchant-initiated payment request.
+     * [Optional]
+     * Enum: "Delayed_charge" "Resubmission" "No_show" "Reauthorization"
+     */
     private MerchantInitiatedReason merchantInitiatedReason;
 
-    @SerializedName("campaign_id")
+    /**
+     * Unique number of the campaign this payment will run in. Required for Afterpay campaign invoices.
+     * [Optional]
+     */
     private Long campaignId;
 
-    @SerializedName("product_type")
+    /**
+     * The product type of the payment. Required for wechatpay and sequra; optional for tamara.
+     * [Optional]
+     */
     private ProductType productType;
 
-    @SerializedName("open_id")
+    /**
+     * The OpenID obtained from WeChat Web Authorization API. Required for Official Account or Mini Program payments.
+     * [Optional]
+     */
     private String openId;
 
-    @SerializedName("original_order_amount")
+    /**
+     * The original order amount when a payment is split. Indicates the full order price.
+     * [Optional]
+     */
     private Long originalOrderAmount;
 
-    @SerializedName("receipt_id")
+    /**
+     * Merchant receipt ID.
+     * [Optional]
+     * max 32 characters
+     */
     private String receiptId;
 
-    @SerializedName("terminal_type")
+    /**
+     * The client-side terminal type: APP, WAP (mobile browser), or WEB (PC browser).
+     * [Optional]
+     * Enum: "APP" "WAP" "WEB"
+     */
     private TerminalType terminalType;
 
-    @SerializedName("os_type")
+    /**
+     * The operating system type. Required when terminal_type is not WEB.
+     * [Optional]
+     * Enum: "ANDROID" "IOS"
+     */
     private OsType osType;
 
-    @SerializedName("invoice_id")
+    /**
+     * Invoice ID number.
+     * [Optional]
+     * max 127 characters
+     */
     private String invoiceId;
 
-    @SerializedName("brand_name")
+    /**
+     * The label that overrides the business name in the PayPal account on PayPal pages.
+     * [Optional]
+     * max 127 characters
+     */
     private String brandName;
 
+    /**
+     * The language and region of the customer in ISO 639-2 format (e.g. en-US).
+     * [Optional]
+     * Pattern: ^[a-z]{2}(?:-[A-Z][a-z]{3})?(?:-(?:[A-Z]{2}))?$
+     * min 2 characters, max 10 characters
+     */
     private String locale;
 
-    @SerializedName("shipping_preference")
+    /**
+     * Shipping preference for PayPal payments.
+     * [Optional]
+     * Enum: "no_shipping" "set_provided_address" "get_from_file"
+     */
     private ShippingPreference shippingPreference;
 
-    @SerializedName("user_action")
+    /**
+     * Property required by PayPal to determine the appropriate payment flow.
+     * [Optional]
+     * Enum: "pay_now" "continue"
+     */
     private UserAction userAction;
 
-    @SerializedName("set_transaction_context")
+    /**
+     * An array of key-value pairs with merchant-specific transaction context data for PayPal.
+     * [Optional]
+     */
     private List<Map<String, String>> setTransactionContext;
 
-    @SerializedName("airline_data")
+    /**
+     * Airline ticket and flight information for the payment.
+     * [Optional]
+     */
     private List<AirlineData> airlineData;
 
-    @SerializedName("otp_value")
+    /**
+     * The accommodation data for hotel or lodging payments.
+     * [Optional]
+     */
+    private List<AccommodationData> accommodationData;
+
+    /**
+     * A one-time password value for OTP-based payment flows.
+     * [Optional]
+     */
     private String otpValue;
 
-    @SerializedName("purchase_country")
+    /**
+     * The two-letter ISO country code of the purchase country.
+     * [Optional]
+     * max 2 characters
+     */
     private CountryCode purchaseCountry;
 
-    @SerializedName("custom_payment_method_ids")
+    /**
+     * Custom payment method IDs (Klarna promo codes) defining which payment options to show.
+     * [Optional]
+     */
     private List<String> customPaymentMethodIds;
 
-    @SerializedName("merchant_callback_url")
+    /**
+     * A URL to notify the customer when the order has been created (used by some APMs).
+     * [Optional]
+     */
     private String merchantCallbackUrl;
 
-    @SerializedName("line_of_business")
+    /**
+     * The line of business that the payment is associated with.
+     * [Optional]
+     */
     private String lineOfBusiness;
 
-    @SerializedName("shipping_delay")
+    /**
+     * The number of days by which the shipping is delayed.
+     * [Optional]
+     */
     private Long shippingDelay;
 
-    @SerializedName("shipping_info")
+    /**
+     * Shipping information for the transaction.
+     * [Optional]
+     */
     private List<ShippingInfo> shippingInfo;
 
-    @SerializedName("provision_network_token")
+    /**
+     * Indicates whether to provision a network token for the payment.
+     * [Optional]
+     */
     private Boolean provisionNetworkToken;
 
-    @SerializedName("pan_preference")
+    /**
+     * Specifies the preferred type of Primary Account Number (PAN): fpan or dpan.
+     * [Optional]
+     * Enum: "fpan" "dpan"
+     */
     private PanProcessedType panPreference;
 
-    @SerializedName("hub_model_origination_country")
+    /**
+     * The ACH service type to use for the payment when source.type is ach.
+     * [Optional]
+     * Enum: "same_day" "standard"
+     */
+    private AchServiceType serviceType;
+
+    /**
+     * The foreign retailer amount the merchant applied to the transaction, in minor currency units.
+     * [Optional]
+     */
+    private Long foreignRetailerAmount;
+
+    /**
+     * A reconciliation identifier for the payment.
+     * [Optional]
+     */
+    private String reconciliationId;
+
+    /**
+     * The aggregator information for this payment.
+     * [Optional]
+     */
+    private Aggregator aggregator;
+
+    /**
+     * The origination country for hub model payments.
+     * [Optional]
+     */
     private CountryCode hubModelOriginationCountry;
 
-    //Previous
+    /**
+     * DLocal-specific processing settings. Used for Previous API only.
+     * [Optional]
+     */
     private DLocalProcessingSettings dlocal;
 
-    @SerializedName("senderInformation")
+    /**
+     * Sender information. Used for Previous API only.
+     * [Optional]
+     */
     private SenderInformation senderInformation;
 
-    @SerializedName("card_type")
+    /**
+     * Specifies whether to process the payment as credit or debit when a combo card is used.
+     * [Optional]
+     * Enum: "credit" "debit"
+     */
     private CardType cardType;
 
-    @SerializedName("affiliate_id")
+    /**
+     * The unique identifier for a Visa-registered ramp provider. Must be alphanumeric.
+     * [Optional]
+     * Pattern: ^[a-zA-Z0-9]{1,15}$
+     * max 15 characters
+     */
     private String affiliateId;
 
-    @SerializedName("affiliate_url")
+    /**
+     * The affiliate URL. Required if you are a Visa-registered ramp provider operating with affiliates.
+     * [Optional]
+     */
     private String affiliateUrl;
 
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/checkout/payments/ThreeDSData.java b/src/main/java/com/checkout/payments/ThreeDSData.java
index 11b0ae05..2bb85d94 100644
--- a/src/main/java/com/checkout/payments/ThreeDSData.java
+++ b/src/main/java/com/checkout/payments/ThreeDSData.java
@@ -2,36 +2,93 @@
 
 import com.checkout.common.Exemption;
 import com.checkout.common.ThreeDSEnrollmentStatus;
-import com.google.gson.annotations.SerializedName;
 import lombok.Data;
 
 @Data
 public final class ThreeDSData {
 
+    /**
+     * Whether the 3DS authentication was downgraded.
+     * [Optional]
+     */
     private Boolean downgraded;
 
+    /**
+     * The 3DS enrollment status of the card.
+     * [Optional]
+     */
     private ThreeDSEnrollmentStatus enrolled;
 
-    @SerializedName("upgrade_reason")
+    /**
+     * The reason for the 3DS upgrade.
+     * [Optional]
+     */
     private String upgradeReason;
 
-    @SerializedName("signature_valid")
+    /**
+     * Whether the 3DS signature is valid.
+     * [Optional]
+     */
     private String signatureValid;
 
-    @SerializedName("authentication_response")
+    /**
+     * The 3DS authentication response code.
+     * [Optional]
+     */
     private String authenticationResponse;
 
+    /**
+     * The 3DS cryptogram (CAVV) for the transaction.
+     * [Optional]
+     */
     private String cryptogram;
 
+    /**
+     * The 3DS transaction identifier (XID).
+     * [Optional]
+     */
     private String xid;
 
+    /**
+     * The 3DS protocol version used for authentication.
+     * [Optional]
+     */
     private String version;
 
+    /**
+     * The 3DS exemption type applied to the payment.
+     * [Optional]
+     */
     private Exemption exemption;
 
-    @SerializedName("exemption_applied")
+    /**
+     * The 3DS exemption type that was applied by the issuer.
+     * [Optional]
+     */
     private String exemptionApplied;
 
+    /**
+     * Whether the cardholder was challenged during authentication.
+     * [Optional]
+     */
     private Boolean challenged;
 
+    /**
+     * The Electronic Commerce Indicator (ECI) value from the 3DS authentication.
+     * [Optional]
+     */
+    private String eci;
+
+    /**
+     * The reason for the authentication status result.
+     * [Optional]
+     */
+    private String authenticationStatusReason;
+
+    /**
+     * The trusted listing status for the cardholder.
+     * [Optional]
+     */
+    private TrustedListing trustedListing;
+
 }
diff --git a/src/main/java/com/checkout/payments/TrustedListing.java b/src/main/java/com/checkout/payments/TrustedListing.java
new file mode 100644
index 00000000..605d078a
--- /dev/null
+++ b/src/main/java/com/checkout/payments/TrustedListing.java
@@ -0,0 +1,20 @@
+package com.checkout.payments;
+
+import lombok.Data;
+
+@Data
+public final class TrustedListing {
+
+    /**
+     * The trusted listing status for the cardholder.
+     * [Optional]
+     */
+    private TrustedListingStatus status;
+
+    /**
+     * The source of the trusted listing entry.
+     * [Optional]
+     */
+    private String source;
+
+}
diff --git a/src/main/java/com/checkout/payments/TrustedListingStatus.java b/src/main/java/com/checkout/payments/TrustedListingStatus.java
new file mode 100644
index 00000000..466691e3
--- /dev/null
+++ b/src/main/java/com/checkout/payments/TrustedListingStatus.java
@@ -0,0 +1,31 @@
+package com.checkout.payments;
+
+import com.google.gson.annotations.SerializedName;
+
+public enum TrustedListingStatus {
+
+    /** 3DS Requestor is allowlisted by cardholder. */
+    @SerializedName("Y")
+    ALLOWLISTED,
+
+    /** 3DS Requestor is not allowlisted by cardholder. */
+    @SerializedName("N")
+    NOT_ALLOWLISTED,
+
+    /** Not eligible as determined by issuer. */
+    @SerializedName("E")
+    NOT_ELIGIBLE,
+
+    /** Pending confirmation by cardholder. */
+    @SerializedName("P")
+    PENDING,
+
+    /** Cardholder rejected. */
+    @SerializedName("R")
+    REJECTED,
+
+    /** Allowlist status unknown, unavailable, or does not apply. */
+    @SerializedName("U")
+    UNKNOWN
+
+}
diff --git a/src/main/java/com/checkout/payments/contexts/PaymentContexts.java b/src/main/java/com/checkout/payments/contexts/PaymentContexts.java
index 4cd4538a..57cb2234 100644
--- a/src/main/java/com/checkout/payments/contexts/PaymentContexts.java
+++ b/src/main/java/com/checkout/payments/contexts/PaymentContexts.java
@@ -3,48 +3,116 @@
 import com.checkout.common.Currency;
 import com.checkout.payments.PaymentType;
 import com.checkout.payments.ShippingDetails;
-import com.google.gson.annotations.SerializedName;
 import lombok.AllArgsConstructor;
 import lombok.Data;
 import lombok.NoArgsConstructor;
 
 import java.util.List;
+import java.util.Map;
 
 @Data
 @AllArgsConstructor
 @NoArgsConstructor
 public class PaymentContexts {
 
+    /**
+     * The payment amount in minor currency units.
+     * [Required]
+     * min 0
+     */
     private Long amount;
 
+    /**
+     * The three-letter ISO currency code.
+     * [Required]
+     * min 3 characters, max 3 characters
+     */
     private Currency currency;
 
-    @SerializedName("payment_type")
+    /**
+     * Must be "Recurring" if the payment is paid in multiple installments.
+     * [Optional]
+     * Enum: "Regular" "Recurring"
+     */
     private PaymentType paymentType;
 
-    @SerializedName("authorization_type")
+    /**
+     * The authorization type for the payment.
+     * [Optional]
+     */
     private String authorizationType;
 
+    /**
+     * Whether to capture the later payment.
+     * [Optional]
+     */
     private Boolean capture;
 
+    /**
+     * The customer details. Required if source.type is StcPay or Tabby.
+     * [Optional]
+     */
     private PaymentContextsCustomerRequest customer;
 
+    /**
+     * The shipping details.
+     * [Optional]
+     */
     private ShippingDetails shipping;
 
+    /**
+     * Use the processing object to influence or override the data during payment processing.
+     * [Optional]
+     */
     private PaymentContextsProcessing processing;
 
-    @SerializedName("processing_channel_id")
+    /**
+     * The processing channel to be used for the payment.
+     * [Optional]
+     * Pattern: ^(pc)_(\w{26})$
+     */
     private String processingChannelId;
 
+    /**
+     * A reference you can later use to identify this Payment Context, such as an order number.
+     * [Optional]
+     * max 50 characters
+     */
     private String reference;
 
+    /**
+     * A description of the Payment Context.
+     * [Optional]
+     * max 100 characters
+     */
     private String description;
 
-    @SerializedName("success_url")
+    /**
+     * For redirect payment methods, this overrides the default success redirect URL configured on your account.
+     * [Optional]
+     * Format: uri
+     * max 1024 characters
+     */
     private String successUrl;
 
-    @SerializedName("failure_url")
+    /**
+     * For redirect payment methods, this overrides the default failure redirect URL configured on your account.
+     * [Optional]
+     * Format: uri
+     * max 1024 characters
+     */
     private String failureUrl;
 
+    /**
+     * The order's line items. Required for Klarna payments.
+     * [Optional]
+     */
     private List<PaymentContextsItems> items;
+
+    /**
+     * A set of key-value pairs to store additional information about the transaction.
+     * Up to 20 fields, max 255 characters per value.
+     * [Optional]
+     */
+    private Map<String, Object> metadata;
 }
diff --git a/src/main/java/com/checkout/payments/contexts/PaymentContextsAccommodationData.java b/src/main/java/com/checkout/payments/contexts/PaymentContextsAccommodationData.java
index 63390f11..298249d9 100644
--- a/src/main/java/com/checkout/payments/contexts/PaymentContextsAccommodationData.java
+++ b/src/main/java/com/checkout/payments/contexts/PaymentContextsAccommodationData.java
@@ -2,7 +2,7 @@
 
 import com.checkout.common.Address;
 import com.checkout.common.CountryCode;
-import com.google.gson.annotations.SerializedName;
+import com.checkout.common.Phone;
 import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Data;
@@ -27,7 +27,6 @@ public final class PaymentContextsAccommodationData {
      * The booking reference.
      * [Optional]
      */
-    @SerializedName("booking_reference")
     private String bookingReference;
 
     /**
@@ -35,7 +34,6 @@ public final class PaymentContextsAccommodationData {
      * [Optional]
      * Format: yyyy-MM-dd
      */
-    @SerializedName("check_in_date")
     private LocalDate checkInDate;
 
     /**
@@ -43,7 +41,6 @@ public final class PaymentContextsAccommodationData {
      * [Optional]
      * Format: yyyy-MM-dd
      */
-    @SerializedName("check_out_date")
     private LocalDate checkOutDate;
 
     /**
@@ -74,20 +71,29 @@ public final class PaymentContextsAccommodationData {
      * The number of rooms booked.
      * [Optional]
      */
-    @SerializedName("number_of_rooms")
     private Integer numberOfRooms;
 
     /**
      * Information about the guests staying at the accommodation.
      * [Optional]
      */
-    @SerializedName("guests")
     private List<PaymentContextsGuests> guests;
 
     /**
      * Information about the rooms booked by the customer.
      * [Optional]
      */
-    @SerializedName("room")
     private List<PaymentContextsAccommodationRoom> room;
+
+    /**
+     * The property's phone information.
+     * [Optional]
+     */
+    private List<Phone> propertyPhone;
+
+    /**
+     * The customer service phone information.
+     * [Optional]
+     */
+    private List<Phone> customerServicePhone;
 }
diff --git a/src/main/java/com/checkout/payments/contexts/PaymentContextsRequest.java b/src/main/java/com/checkout/payments/contexts/PaymentContextsRequest.java
index 60406925..211705bf 100644
--- a/src/main/java/com/checkout/payments/contexts/PaymentContextsRequest.java
+++ b/src/main/java/com/checkout/payments/contexts/PaymentContextsRequest.java
@@ -11,6 +11,7 @@
 import lombok.ToString;
 
 import java.util.List;
+import java.util.Map;
 
 @Data
 @ToString(callSuper = true)
@@ -18,6 +19,10 @@
 @NoArgsConstructor
 public final class PaymentContextsRequest extends PaymentContexts {
 
+    /**
+     * The source of the payment. Discriminated by type: klarna, paypal, stcpay, tabby.
+     * [Required]
+     */
     private AbstractRequestSource source;
 
     @Builder
@@ -36,10 +41,11 @@ private PaymentContextsRequest(
             final String failureUrl,
             final List<PaymentContextsItems> items,
             final String authorizationType,
-            final PaymentContextsCustomerRequest customer
+            final PaymentContextsCustomerRequest customer,
+            final Map<String, Object> metadata
     ) {
         super(amount, currency, paymentType, authorizationType, capture, customer, shipping, processing,
-                processingChannelId, reference, description, successUrl, failureUrl, items);
+                processingChannelId, reference, description, successUrl, failureUrl, items, metadata);
         this.source = source;
     }
 }
diff --git a/src/main/java/com/checkout/payments/hosted/HostedPaymentRequest.java b/src/main/java/com/checkout/payments/hosted/HostedPaymentRequest.java
index efa5c5bc..801428ac 100644
--- a/src/main/java/com/checkout/payments/hosted/HostedPaymentRequest.java
+++ b/src/main/java/com/checkout/payments/hosted/HostedPaymentRequest.java
@@ -30,81 +30,203 @@
 @Builder
 public final class HostedPaymentRequest {
 
+    /**
+     * The three-letter ISO currency code of the payment.
+     * [Required]
+     * min 3 characters, max 3 characters
+     */
     private Currency currency;
 
+    /**
+     * The billing information for the payment, including address and phone.
+     * [Required]
+     */
     private BillingInformation billing;
 
-    @SerializedName("success_url")
+    /**
+     * For redirect payment methods, overrides the default success redirect URL configured on your account.
+     * [Required]
+     * Format: uri
+     * max 255 characters
+     */
     private String successUrl;
 
-    @SerializedName("cancel_url")
+    /**
+     * The URL to which the customer should be directed if they cancel the payment.
+     * [Required]
+     * Format: uri
+     * max 255 characters
+     */
     private String cancelUrl;
 
-    @SerializedName("failure_url")
+    /**
+     * For redirect payment methods, overrides the default failure redirect URL configured on your account.
+     * [Required]
+     * Format: uri
+     * max 255 characters
+     */
     private String failureUrl;
 
+    /**
+     * The payment amount in minor currency units. The exact format depends on the currency.
+     * [Optional]
+     * min 0
+     */
     private Long amount;
 
+    /**
+     * The type of payment. Must be specified for card payments where the cardholder is not present.
+     * [Optional]
+     * Enum: "Regular" "Recurring"
+     */
     @Builder.Default
-    @SerializedName("payment_type")
     private PaymentType paymentType = PaymentType.REGULAR;
 
-    @SerializedName("payment_ip")
+    /**
+     * @deprecated Deprecated in the API on 2025-03-11. Use {@code risk.device.network.ipv4} or {@code risk.device.network.ipv6} instead.
+     */
+    @Deprecated
     private String paymentIp;
 
-    @SerializedName("billing_descriptor")
+    /**
+     * An optional description displayed on the customer's statement identifying a purchase.
+     * [Optional]
+     */
     private BillingDescriptor billingDescriptor;
 
+    /**
+     * A reference you can use to identify the payment, such as an order number.
+     * [Optional]
+     */
     private String reference;
 
+    /**
+     * A description of the payment.
+     * [Optional]
+     * max 100 characters
+     */
     private String description;
 
-    @SerializedName("display_name")
+    /**
+     * The merchant name to display to customers on the checkout page.
+     * [Optional]
+     */
     private String displayName;
 
-    @SerializedName("processing_channel_id")
+    /**
+     * The processing channel to be used for the payment.
+     * [Optional]
+     * Pattern: ^(pc)_(\w{26})$
+     */
     private String processingChannelId;
 
-    @SerializedName("amount_allocations")
+    /**
+     * The amount allocations for marketplace or split payments.
+     * [Optional]
+     */
     private List<AmountAllocations> amountAllocations;
 
+    /**
+     * The customer details.
+     * [Optional]
+     */
     private CustomerRequest customer;
 
+    /**
+     * The shipping details.
+     * [Optional]
+     */
     private ShippingDetails shipping;
 
+    /**
+     * The recipient of the payment. Used for financial regulations compliance.
+     * [Optional]
+     */
     private PaymentRecipient recipient;
 
+    /**
+     * Use the processing object to influence or override data during payment processing.
+     * [Optional]
+     */
     private ProcessingSettings processing;
 
-    @SerializedName("allow_payment_methods")
+    /**
+     * Specifies which payment method options to present to the customer.
+     * [Optional]
+     */
     private List<PaymentSourceType> allowPaymentMethods;
 
-    @SerializedName("disabled_payment_methods")
+    /**
+     * Specifies which payment method options to hide from the customer.
+     * [Optional]
+     */
     private List<PaymentSourceType> disabledPaymentMethods;
 
+    /**
+     * The line items or products included in the purchase.
+     * [Optional]
+     */
     private List<Product> products;
 
+    /**
+     * The risk assessment configuration for the payment.
+     * [Optional]
+     */
     private RiskRequest risk;
 
-    @SerializedName("customer_retry")
+    /**
+     * The customer retry configuration for failed payments.
+     * [Optional]
+     */
     private PaymentRetryRequest customerRetry;
 
+    /**
+     * The sender of the payment. Required for financial regulations in some jurisdictions.
+     * [Optional]
+     */
     private Sender sender;
 
+    /**
+     * Key-value pairs to store additional information about the transaction.
+     * [Optional]
+     */
     private Map<String, Object> metadata;
 
+    /**
+     * Creates a translated version of the hosted page in the specified language.
+     * [Optional]
+     */
     private LocaleType locale;
 
+    /**
+     * The 3D Secure (3DS) authentication configuration for the payment.
+     * [Optional]
+     */
     @SerializedName("3ds")
     private ThreeDSRequest threeDS;
 
+    /**
+     * Whether to capture the payment immediately (if applicable).
+     * [Optional]
+     */
     private Boolean capture;
 
-    @SerializedName("capture_on")
+    /**
+     * The date and time at which the payment should be captured (ISO 8601).
+     * [Optional]
+     * Format: date-time (RFC 3339)
+     */
     private Instant captureOn;
 
+    /**
+     * The payment instruction details, such as purpose of payment.
+     * [Optional]
+     */
     private PaymentInstruction instruction;
 
-    @SerializedName("payment_method_configuration")
+    /**
+     * The payment method configuration for stored card and wallet methods.
+     * [Optional]
+     */
     private PaymentMethodConfiguration paymentMethodConfiguration;
 }
diff --git a/src/main/java/com/checkout/payments/links/PaymentLinkRequest.java b/src/main/java/com/checkout/payments/links/PaymentLinkRequest.java
index 86ccbbf6..b612e4e4 100644
--- a/src/main/java/com/checkout/payments/links/PaymentLinkRequest.java
+++ b/src/main/java/com/checkout/payments/links/PaymentLinkRequest.java
@@ -30,77 +30,190 @@
 @Builder
 public final class PaymentLinkRequest {
 
+    /**
+     * The payment amount in minor currency units. The exact format depends on the currency.
+     * [Required]
+     * min 0
+     */
     private Long amount;
 
+    /**
+     * The three-letter ISO currency code of the payment.
+     * [Required]
+     * min 3 characters, max 3 characters
+     */
     private Currency currency;
 
+    /**
+     * The billing information for the payment, including address and phone.
+     * [Required]
+     */
     private BillingInformation billing;
 
-    @SerializedName("payment_type")
+    /**
+     * The type of payment. Must be specified for card payments where the cardholder is not present.
+     * [Optional]
+     * Enum: "Regular" "Recurring" "MOTO" "Installment" "Unscheduled"
+     */
     private PaymentType paymentType;
 
-    @SerializedName("payment_ip")
+    /**
+     * @deprecated Deprecated in the API on 2025-03-11. Use {@code risk.device.network.ipv4} or {@code risk.device.network.ipv6} instead.
+     */
+    @Deprecated
     private String paymentIp;
 
-    @SerializedName("billing_descriptor")
+    /**
+     * An optional description displayed on the customer's statement identifying a purchase.
+     * [Optional]
+     */
     private BillingDescriptor billingDescriptor;
 
+    /**
+     * A reference you can use to identify the payment, such as an order number.
+     * [Optional]
+     */
     private String reference;
 
+    /**
+     * A description of the payment.
+     * [Optional]
+     * max 100 characters
+     */
     private String description;
 
-    @SerializedName("display_name")
+    /**
+     * The merchant name to display to customers on the checkout page.
+     * [Optional]
+     */
     private String displayName;
 
-    @SerializedName("processing_channel_id")
+    /**
+     * The processing channel to be used for the payment.
+     * [Optional]
+     * Pattern: ^(pc)_(\w{26})$
+     */
     private String processingChannelId;
 
-    @SerializedName("amount_allocations")
+    /**
+     * The amount allocations for marketplace or split payments.
+     * [Optional]
+     */
     private List<AmountAllocations> amountAllocations;
 
-    @SerializedName("expires_in")
+    /**
+     * The time for which the Payment Link remains valid, in seconds.
+     * [Optional]
+     */
     private Integer expiresIn;
 
+    /**
+     * The customer details.
+     * [Optional]
+     */
     private CustomerRequest customer;
 
+    /**
+     * The shipping details.
+     * [Optional]
+     */
     private ShippingDetails shipping;
 
+    /**
+     * The recipient of the payment. Used for financial regulations compliance.
+     * [Optional]
+     */
     private PaymentRecipient recipient;
 
+    /**
+     * Use the processing object to influence or override data during payment processing.
+     * [Optional]
+     */
     private ProcessingSettings processing;
 
-    @SerializedName("allow_payment_methods")
+    /**
+     * Specifies which payment method options to present to the customer.
+     * [Optional]
+     */
     private List<PaymentSourceType> allowPaymentMethods;
 
-    @SerializedName("disabled_payment_methods")
+    /**
+     * Specifies which payment method options to hide from the customer.
+     * [Optional]
+     */
     private List<PaymentSourceType> disabledPaymentMethods;
 
+    /**
+     * The line items or products included in the purchase.
+     * [Optional]
+     */
     private List<Product> products;
 
+    /**
+     * Key-value pairs to store additional information about the transaction.
+     * [Optional]
+     */
     private Map<String, Object> metadata;
 
+    /**
+     * The 3D Secure (3DS) authentication configuration for the payment.
+     * [Optional]
+     */
     @SerializedName("3ds")
     private ThreeDSRequest threeDS;
 
+    /**
+     * The risk assessment configuration for the payment.
+     * [Optional]
+     */
     private RiskRequest risk;
 
-    @SerializedName("customer_retry")
+    /**
+     * The customer retry configuration for failed payments.
+     * [Optional]
+     */
     private PaymentRetryRequest customerRetry;
 
+    /**
+     * The sender of the payment. Required for financial regulations in some jurisdictions.
+     * [Optional]
+     */
     private PaymentSender sender;
 
-    @SerializedName("return_url")
+    /**
+     * If provided, the success page will include a button that redirects the customer to this URL.
+     * [Optional]
+     */
     private String returnUrl;
 
+    /**
+     * Creates a translated version of the hosted page in the specified language.
+     * [Optional]
+     */
     private LocaleType locale;
 
+    /**
+     * Whether to capture the payment immediately (if applicable).
+     * [Optional]
+     */
     private boolean capture;
 
-    @SerializedName("capture_on")
+    /**
+     * The date and time at which the payment should be captured (ISO 8601).
+     * [Optional]
+     * Format: date-time (RFC 3339)
+     */
     private Instant captureOn;
 
+    /**
+     * The payment instruction details, such as purpose of payment.
+     * [Optional]
+     */
     private PaymentInstruction instruction;
 
-    @SerializedName("payment_method_configuration")
+    /**
+     * The payment method configuration for stored card and wallet methods.
+     * [Optional]
+     */
     private PaymentMethodConfiguration paymentMethodConfiguration;
 }
diff --git a/src/main/java/com/checkout/payments/request/DowntimeRetryRequest.java b/src/main/java/com/checkout/payments/request/DowntimeRetryRequest.java
new file mode 100644
index 00000000..422ace8d
--- /dev/null
+++ b/src/main/java/com/checkout/payments/request/DowntimeRetryRequest.java
@@ -0,0 +1,20 @@
+package com.checkout.payments.request;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+@Data
+@Builder
+@AllArgsConstructor
+@NoArgsConstructor
+public final class DowntimeRetryRequest {
+
+    /**
+     * Whether downtime retries are enabled.
+     * [Optional]
+     */
+    private Boolean enabled;
+
+}
diff --git a/src/main/java/com/checkout/payments/request/DunningRetryRequest.java b/src/main/java/com/checkout/payments/request/DunningRetryRequest.java
new file mode 100644
index 00000000..ee2d2226
--- /dev/null
+++ b/src/main/java/com/checkout/payments/request/DunningRetryRequest.java
@@ -0,0 +1,32 @@
+package com.checkout.payments.request;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+@Data
+@Builder
+@AllArgsConstructor
+@NoArgsConstructor
+public final class DunningRetryRequest {
+
+    /**
+     * Whether dunning retries are enabled.
+     * [Optional]
+     */
+    private Boolean enabled;
+
+    /**
+     * The maximum number of retry attempts.
+     * [Optional]
+     */
+    private Integer maxAttempts;
+
+    /**
+     * The number of days after which retries stop.
+     * [Optional]
+     */
+    private Integer endAfterDays;
+
+}
diff --git a/src/main/java/com/checkout/payments/request/PaymentRequest.java b/src/main/java/com/checkout/payments/request/PaymentRequest.java
index 0abe92b8..7bd5158f 100644
--- a/src/main/java/com/checkout/payments/request/PaymentRequest.java
+++ b/src/main/java/com/checkout/payments/request/PaymentRequest.java
@@ -30,120 +30,249 @@
 @Data
 @Builder
 public final class PaymentRequest {
-    
-    @SerializedName("payment_context_id")
+
+    /**
+     * The unique identifier of a Payment Context. Used to initiate a payment from a context.
+     * [Optional]
+     */
     private String paymentContextId;
 
+    /**
+     * The source of the payment. Discriminated by type.
+     * [Optional]
+     */
     private AbstractRequestSource source;
 
+    /**
+     * The payment amount in minor currency units. To perform a card verification, do not provide
+     * the amount or provide a value of 0.
+     * [Optional]
+     * min 0
+     */
     private Long amount;
 
+    /**
+     * The three-letter ISO currency code of the payment.
+     * [Required]
+     * min 3 characters, max 3 characters
+     */
     private Currency currency;
 
+    /**
+     * The type of payment. Required for card payments where the cardholder is not present,
+     * such as recurring or MOTO payments. For MITs, must not be set to Regular.
+     * [Optional]
+     * Enum: "Regular" "Recurring" "MOTO" "Installment" "PayLater" "Unscheduled"
+     */
     @Builder.Default
-    @SerializedName("payment_type")
     private PaymentType paymentType = PaymentType.REGULAR;
 
-    @SerializedName("payment_plan")
+    /**
+     * The details of a recurring subscription or installment.
+     * [Optional]
+     */
     private PaymentPlan paymentPlan;
 
-    @SerializedName("merchant_initiated")
+    /**
+     * Whether the payment is a merchant-initiated transaction (MIT).
+     * Must be set to true for all MITs. If true, payment_type must not be Regular.
+     * [Optional]
+     */
     private Boolean merchantInitiated;
 
+    /**
+     * A reference you can use to identify the payment, such as an order number.
+     * [Optional]
+     * max 80 characters
+     */
     private String reference;
 
+    /**
+     * A description of the payment.
+     * [Optional]
+     * max 100 characters
+     */
     private String description;
 
+    /**
+     * Information required to authenticate the payment.
+     * [Optional]
+     */
     private Authentication authentication;
 
-    @SerializedName("authorization_type")
+    /**
+     * The authorization type for the payment.
+     * [Optional]
+     * Enum: "Final" "Estimated"
+     */
     private AuthorizationType authorizationType;
 
-    @SerializedName("partial_authorization")
+    /**
+     * The partial authorization configuration for the payment.
+     * [Optional]
+     */
     private PartialAuthorization partialAuthorization;
 
+    /**
+     * Whether to capture the payment immediately (if applicable).
+     * [Optional]
+     */
     private Boolean capture;
 
-    @SerializedName("capture_on")
+    /**
+     * A timestamp (ISO 8601) that determines when the payment should be captured.
+     * Providing this field will automatically set capture to true.
+     * [Optional]
+     * Format: date-time (RFC 3339)
+     */
     private Instant captureOn;
 
     /**
      * The date and time when the Multibanco payment expires in UTC.
-     * <p>
      * [Optional]
-     * </p>
      * Format: date-time (ISO 8601)
      */
-    @SerializedName("expire_on")
     private Instant expireOn;
 
+    /**
+     * The customer details for the payment.
+     * [Optional]
+     */
     private CustomerRequest customer;
 
-    @SerializedName("billing_descriptor")
+    /**
+     * An optional description displayed on the customer's statement identifying a purchase.
+     * [Optional]
+     */
     private BillingDescriptor billingDescriptor;
 
+    /**
+     * The shipping details for the payment.
+     * [Optional]
+     */
     private ShippingDetails shipping;
 
+    /**
+     * Information required for 3D Secure authentication payments.
+     * [Optional]
+     */
     @SerializedName("3ds")
     private ThreeDSRequest threeDS;
 
-    @SerializedName("processing_channel_id")
+    /**
+     * The processing channel to be used for the payment.
+     * [Optional]
+     * Pattern: ^(pc)_(\w{26})$
+     */
     private String processingChannelId;
 
-    @SerializedName("previous_payment_id")
+    /**
+     * An identifier that links the payment to an existing series of payments.
+     * Only pass this field for merchant-initiated transactions (MITs) in a recurring payment series.
+     * [Optional]
+     * max 100 characters
+     */
     private String previousPaymentId;
 
+    /**
+     * The risk assessment configuration for the payment.
+     * [Optional]
+     */
     private RiskRequest risk;
 
-    @SerializedName("success_url")
+    /**
+     * For redirect payment methods, overrides the default success redirect URL configured on your account.
+     * [Optional]
+     * Format: uri
+     * max 1024 characters
+     */
     private String successUrl;
 
-    @SerializedName("failure_url")
+    /**
+     * For redirect payment methods, overrides the default failure redirect URL configured on your account.
+     * [Optional]
+     * Format: uri
+     * max 1024 characters
+     */
     private String failureUrl;
 
-    @SerializedName("payment_ip")
+    /**
+     * @deprecated Deprecated in the API on 2025-03-11. Use {@code risk.device.network.ipv4} or {@code risk.device.network.ipv6} instead.
+     */
+    @Deprecated
     private String paymentIp;
 
+    /**
+     * The sender of the payment. Required for financial regulations in some jurisdictions.
+     * [Optional]
+     */
     private PaymentSender sender;
 
+    /**
+     * The recipient of the payment. Used for financial regulations compliance.
+     * [Optional]
+     */
     private PaymentRecipient recipient;
 
     /**
-     * @deprecated This property will be removed in the future, and should be used
-     * {@link PaymentRequest#amountAllocations} instead
+     * @deprecated Use {@link PaymentRequest#amountAllocations} instead.
      */
     @Deprecated
     private MarketplaceData marketplace;
 
-    @SerializedName("amount_allocations")
+    /**
+     * The amount allocations for marketplace or split payments.
+     * [Optional]
+     */
     private List<AmountAllocations> amountAllocations;
 
+    /**
+     * Use the processing object to influence or override data during payment processing.
+     * [Optional]
+     */
     private ProcessingSettings processing;
 
+    /**
+     * The line items or products included in the purchase.
+     * [Optional]
+     */
     private List<ProductRequest> items;
 
+    /**
+     * The retry configuration for failed payment attempts.
+     * [Optional]
+     */
     private PaymentRetryRequest retry;
 
     /**
-     * The details of the subscription.
-     * <p>
+     * The details of the subscription associated with this payment.
      * [Optional]
-     * </p>
      */
     private PaymentSubscription subscription;
 
+    /**
+     * Key-value pairs to store additional information about the transaction.
+     * Supports string, number, and boolean fields. Max 20 fields; each value max 255 characters.
+     * [Optional]
+     */
     @Builder.Default
     private Map<String, Object> metadata = new HashMap<>();
 
+    /**
+     * The segment data for the payment, used for analytics and reporting.
+     * [Optional]
+     */
     private PaymentSegment segment;
 
+    /**
+     * The payment instruction details, such as purpose of payment.
+     * [Optional]
+     */
     private PaymentInstruction instruction;
 
     /**
      * Controls processor attempts at the payment level.
-     * <p>
      * [Optional]
-     * </p>
      */
     private PaymentRouting routing;
 
diff --git a/src/main/java/com/checkout/payments/request/PaymentRetryRequest.java b/src/main/java/com/checkout/payments/request/PaymentRetryRequest.java
index 9b9a05ee..0603d866 100644
--- a/src/main/java/com/checkout/payments/request/PaymentRetryRequest.java
+++ b/src/main/java/com/checkout/payments/request/PaymentRetryRequest.java
@@ -1,6 +1,5 @@
 package com.checkout.payments.request;
 
-import com.google.gson.annotations.SerializedName;
 import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Data;
@@ -12,12 +11,38 @@
 @NoArgsConstructor
 public final class PaymentRetryRequest {
 
+    /**
+     * Configuration of asynchronous Dunning retries.
+     * [Optional]
+     */
+    private DunningRetryRequest dunning;
+
+    /**
+     * Configuration of asynchronous Downtime retries.
+     * [Optional]
+     */
+    private DowntimeRetryRequest downtime;
+
+    // ========================================
+    // Deprecated — use dunning.enabled instead
+    // ========================================
+
+    /**
+     * @deprecated Use {@link DunningRetryRequest#enabled} via {@link #dunning} instead.
+     */
+    @Deprecated
     private Boolean enabled;
 
-    @SerializedName("max_attempts")
+    /**
+     * @deprecated Use {@link DunningRetryRequest#maxAttempts} via {@link #dunning} instead.
+     */
+    @Deprecated
     private Integer maxAttempts;
 
-    @SerializedName("end_after_days")
+    /**
+     * @deprecated Use {@link DunningRetryRequest#endAfterDays} via {@link #dunning} instead.
+     */
+    @Deprecated
     private Integer endAfterDays;
 
 }
diff --git a/src/main/java/com/checkout/payments/request/PayoutRequest.java b/src/main/java/com/checkout/payments/request/PayoutRequest.java
index cbb7e39f..4ebfc314 100644
--- a/src/main/java/com/checkout/payments/request/PayoutRequest.java
+++ b/src/main/java/com/checkout/payments/request/PayoutRequest.java
@@ -5,7 +5,6 @@
 import com.checkout.payments.request.destination.PaymentRequestDestination;
 import com.checkout.payments.request.source.PayoutRequestSource;
 import com.checkout.payments.sender.PaymentSender;
-import com.google.gson.annotations.SerializedName;
 import lombok.Builder;
 import lombok.Data;
 
@@ -15,28 +14,82 @@
 @Builder
 public final class PayoutRequest {
 
+    /**
+     * The source of the payout. Discriminated by type.
+     * [Required]
+     */
     private PayoutRequestSource source;
 
+    /**
+     * The destination of the payout. Discriminated by type.
+     * [Required]
+     */
     private PaymentRequestDestination destination;
 
+    /**
+     * The amount to pay out in minor currency units.
+     * [Optional]
+     * min 0
+     */
     private Long amount;
 
+    /**
+     * The three-letter ISO 4217 currency code for the payout currency.
+     * [Required]
+     */
     private Currency currency;
 
+    /**
+     * A custom reference to identify the payout, such as an order number.
+     * [Optional]
+     * max 50 characters
+     */
     private String reference;
 
-    @SerializedName("billing_descriptor")
+    /**
+     * An optional description displayed on the recipient's statement identifying the payout.
+     * [Optional]
+     */
     private PayoutBillingDescriptor billingDescriptor;
 
+    /**
+     * The sender of the payout. Required for financial regulations in some jurisdictions.
+     * [Optional]
+     */
     private PaymentSender sender;
 
+    /**
+     * Additional details about the payout instruction, such as purpose of payment.
+     * [Required]
+     */
     private PaymentInstruction instruction;
 
-    @SerializedName("processing_channel_id")
+    /**
+     * The processing channel to be used for the payout.
+     * [Required]
+     * Pattern: ^(pc)_(\w{26})$
+     * max 29 characters
+     */
     private String processingChannelId;
 
+    /**
+     * Use the processing object to influence or override data during payout processing.
+     * [Optional]
+     */
     private ProcessingSettings processing;
 
+    /**
+     * The business segment dimension details for this payout.
+     * At least one dimension (brand, business_category, or market) required.
+     * [Optional]
+     */
+    private PaymentSegment segment;
+
+    /**
+     * Key-value pairs to store additional information about the payout.
+     * Supports primitive data types only; objects and arrays are not supported.
+     * [Optional]
+     */
     private Map<String, Object> metadata;
 
 }
diff --git a/src/main/java/com/checkout/payments/request/source/AbstractRequestSource.java b/src/main/java/com/checkout/payments/request/source/AbstractRequestSource.java
index f6f31bde..47e56c89 100644
--- a/src/main/java/com/checkout/payments/request/source/AbstractRequestSource.java
+++ b/src/main/java/com/checkout/payments/request/source/AbstractRequestSource.java
@@ -6,6 +6,10 @@
 @Data
 public abstract class AbstractRequestSource {
 
+    /**
+     * The payment source type.
+     * [Required]
+     */
     protected final PaymentSourceType type;
 
     protected AbstractRequestSource(final PaymentSourceType type) {
diff --git a/src/main/java/com/checkout/payments/request/source/PayoutRequestCurrencyAccountSource.java b/src/main/java/com/checkout/payments/request/source/PayoutRequestCurrencyAccountSource.java
index 5446f09c..c8a60c0c 100644
--- a/src/main/java/com/checkout/payments/request/source/PayoutRequestCurrencyAccountSource.java
+++ b/src/main/java/com/checkout/payments/request/source/PayoutRequestCurrencyAccountSource.java
@@ -12,6 +12,10 @@
 @ToString(callSuper = true)
 public final class PayoutRequestCurrencyAccountSource extends PayoutRequestSource {
 
+    /**
+     * The currency account identifier.
+     * [Required]
+     */
     private String id;
 
     @Builder
diff --git a/src/main/java/com/checkout/payments/request/source/PayoutRequestEntitySource.java b/src/main/java/com/checkout/payments/request/source/PayoutRequestEntitySource.java
index 8e94e2d1..22efa909 100644
--- a/src/main/java/com/checkout/payments/request/source/PayoutRequestEntitySource.java
+++ b/src/main/java/com/checkout/payments/request/source/PayoutRequestEntitySource.java
@@ -12,6 +12,10 @@
 @ToString(callSuper = true)
 public final class PayoutRequestEntitySource extends PayoutRequestSource {
 
+    /**
+     * The entity identifier.
+     * [Required]
+     */
     private String id;
 
     @Builder
@@ -25,4 +29,4 @@ public PayoutRequestEntitySource() {
         super(PayoutSourceType.ENTITY);
     }
 
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/checkout/payments/request/source/PayoutRequestSource.java b/src/main/java/com/checkout/payments/request/source/PayoutRequestSource.java
index cdfdedcf..5aae2188 100644
--- a/src/main/java/com/checkout/payments/request/source/PayoutRequestSource.java
+++ b/src/main/java/com/checkout/payments/request/source/PayoutRequestSource.java
@@ -7,8 +7,16 @@
 @AllArgsConstructor
 public abstract class PayoutRequestSource {
 
+    /**
+     * The payout source type.
+     * [Required]
+     */
     protected PayoutSourceType type;
 
+    /**
+     * The amount to debit from the source. If not provided, the full payment amount is used.
+     * [Optional]
+     */
     protected Long amount;
 
     protected PayoutRequestSource(final PayoutSourceType type) {
diff --git a/src/main/java/com/checkout/payments/request/source/RequestBankAccountSource.java b/src/main/java/com/checkout/payments/request/source/RequestBankAccountSource.java
index 87ef573d..d0f6ffa7 100644
--- a/src/main/java/com/checkout/payments/request/source/RequestBankAccountSource.java
+++ b/src/main/java/com/checkout/payments/request/source/RequestBankAccountSource.java
@@ -4,7 +4,6 @@
 import com.checkout.common.AccountType;
 import com.checkout.common.CountryCode;
 import com.checkout.common.PaymentSourceType;
-import com.google.gson.annotations.SerializedName;
 import lombok.Builder;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
@@ -17,21 +16,40 @@
 @ToString(callSuper = true)
 public final class RequestBankAccountSource extends AbstractRequestSource {
 
-    @SerializedName("payment_method")
+    /**
+     * The payment method to use. For example, "ach".
+     * [Optional]
+     */
     private String paymentMethod;
 
-    @SerializedName("account_type")
+    /**
+     * The type of account.
+     * [Optional]
+     */
     private AccountType accountType;
 
+    /**
+     * The two-letter ISO country code of the bank account.
+     * [Optional]
+     */
     private CountryCode country;
 
-    @SerializedName("account_number")
+    /**
+     * The account number.
+     * [Optional]
+     */
     private String accountNumber;
 
-    @SerializedName("bank_code")
+    /**
+     * The bank routing code.
+     * [Optional]
+     */
     private String bankCode;
 
-    @SerializedName("account_holder")
+    /**
+     * The account holder's details.
+     * [Optional]
+     */
     private AccountHolder accountHolder;
 
     public RequestBankAccountSource() {
diff --git a/src/main/java/com/checkout/payments/request/source/RequestCardSource.java b/src/main/java/com/checkout/payments/request/source/RequestCardSource.java
index ddd352c0..d3ab9930 100644
--- a/src/main/java/com/checkout/payments/request/source/RequestCardSource.java
+++ b/src/main/java/com/checkout/payments/request/source/RequestCardSource.java
@@ -4,7 +4,6 @@
 import com.checkout.common.Address;
 import com.checkout.common.PaymentSourceType;
 import com.checkout.common.Phone;
-import com.google.gson.annotations.SerializedName;
 import lombok.Builder;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
@@ -17,29 +16,64 @@
 @ToString(callSuper = true)
 public final class RequestCardSource extends AbstractRequestSource {
 
+    /**
+     * The card number (without separators). Write-only.
+     * [Optional]
+     */
     private String number;
 
-    @SerializedName("expiry_month")
+    /**
+     * The expiry month of the card.
+     * [Optional]
+     */
     private Integer expiryMonth;
 
-    @SerializedName("expiry_year")
+    /**
+     * The expiry year of the card.
+     * [Optional]
+     */
     private Integer expiryYear;
 
+    /**
+     * The cardholder's name. Write-only.
+     * [Optional]
+     */
     private String name;
 
+    /**
+     * The card verification value/code. 3 digits, except for American Express (4 digits). Write-only.
+     * [Optional]
+     */
     private String cvv;
 
+    /**
+     * Set to true for payments that use stored card details. Write-only.
+     * [Optional]
+     */
     private Boolean stored;
 
-    @SerializedName("store_for_future_use")
+    /**
+     * Set to true if you intend to reuse the payment credentials in subsequent payments. Write-only.
+     * [Optional]
+     */
     private Boolean storeForFutureUse;
 
-    @SerializedName("billing_address")
+    /**
+     * The payment source owner's billing address.
+     * [Optional]
+     */
     private Address billingAddress;
 
+    /**
+     * The payment source owner's phone number.
+     * [Optional]
+     */
     private Phone phone;
 
-    @SerializedName("account_holder")
+    /**
+     * The card account holder's details.
+     * [Optional]
+     */
     private AccountHolder accountHolder;
 
     @Builder
diff --git a/src/main/java/com/checkout/payments/request/source/RequestCustomerSource.java b/src/main/java/com/checkout/payments/request/source/RequestCustomerSource.java
index 55b44694..024ad23d 100644
--- a/src/main/java/com/checkout/payments/request/source/RequestCustomerSource.java
+++ b/src/main/java/com/checkout/payments/request/source/RequestCustomerSource.java
@@ -1,8 +1,9 @@
 package com.checkout.payments.request.source;
 
 import com.checkout.common.AccountHolder;
+import com.checkout.common.Address;
 import com.checkout.common.PaymentSourceType;
-import com.google.gson.annotations.SerializedName;
+import com.checkout.common.Phone;
 import lombok.Builder;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
@@ -15,17 +16,49 @@
 @ToString(callSuper = true)
 public final class RequestCustomerSource extends AbstractRequestSource {
 
+    /**
+     * The unique identifier of an existing customer.
+     * [Optional]
+     * Pattern: ^(cus)_(\w{26})$
+     */
     private String id;
 
-    @SerializedName("account_holder")
+    /**
+     * The customer's billing address.
+     * [Optional]
+     */
+    private Address billingAddress;
+
+    /**
+     * The customer's phone number.
+     * [Optional]
+     */
+    private Phone phone;
+
+    /**
+     * The account holder information for the customer.
+     * [Optional]
+     */
     private AccountHolder accountHolder;
 
+    /**
+     * Whether to update the stored customer information with the data provided.
+     * [Optional]
+     */
+    private Boolean allowUpdate;
+
     @Builder
     private RequestCustomerSource(final String id,
-                                  final AccountHolder accountHolder) {
+                                  final Address billingAddress,
+                                  final Phone phone,
+                                  final AccountHolder accountHolder,
+                                  final Boolean allowUpdate) {
         super(PaymentSourceType.CUSTOMER);
         this.id = id;
+        this.billingAddress = billingAddress;
+        this.phone = phone;
         this.accountHolder = accountHolder;
+        this.allowUpdate = allowUpdate;
     }
 
     public RequestCustomerSource() {
diff --git a/src/main/java/com/checkout/payments/request/source/RequestIdSource.java b/src/main/java/com/checkout/payments/request/source/RequestIdSource.java
index aa1c66a8..aeebbd4b 100644
--- a/src/main/java/com/checkout/payments/request/source/RequestIdSource.java
+++ b/src/main/java/com/checkout/payments/request/source/RequestIdSource.java
@@ -1,8 +1,9 @@
 package com.checkout.payments.request.source;
 
 import com.checkout.common.AccountHolder;
+import com.checkout.common.Address;
 import com.checkout.common.PaymentSourceType;
-import com.google.gson.annotations.SerializedName;
+import com.checkout.common.Phone;
 import lombok.Builder;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
@@ -15,35 +16,82 @@
 @ToString(callSuper = true)
 public final class RequestIdSource extends AbstractRequestSource {
 
+    /**
+     * The payment instrument identifier.
+     * [Required]
+     * Pattern: ^(src)_(\w{26})$
+     */
     private String id;
 
+    /**
+     * The card verification value (CVV) of the card.
+     * [Optional]
+     * min 3 characters, max 4 characters
+     */
     private String cvv;
 
-    @SerializedName("payment_method")
+    /**
+     * The payment method to be used.
+     * [Optional]
+     */
     private String paymentMethod;
 
+    /**
+     * Whether this payment instrument was previously stored for future use.
+     * [Optional]
+     */
     private Boolean stored;
 
-    @SerializedName("store_for_future_use")
+    /**
+     * Whether to store the payment instrument for future use.
+     * [Optional]
+     */
     private Boolean storeForFutureUse;
 
-    @SerializedName("account_holder")
+    /**
+     * The billing address associated with the payment instrument.
+     * [Optional]
+     */
+    private Address billingAddress;
+
+    /**
+     * The phone number associated with the payment instrument.
+     * [Optional]
+     */
+    private Phone phone;
+
+    /**
+     * The account holder information for the payment instrument.
+     * [Optional]
+     */
     private AccountHolder accountHolder;
 
+    /**
+     * Whether to update the stored instrument information with the data provided.
+     * [Optional]
+     */
+    private Boolean allowUpdate;
+
     @Builder
     private RequestIdSource(final String id,
                             final String cvv,
                             final String paymentMethod,
                             final Boolean stored,
                             final Boolean storeForFutureUse,
-                            final AccountHolder accountHolder) {
+                            final Address billingAddress,
+                            final Phone phone,
+                            final AccountHolder accountHolder,
+                            final Boolean allowUpdate) {
         super(PaymentSourceType.ID);
         this.id = id;
         this.cvv = cvv;
         this.paymentMethod = paymentMethod;
         this.stored = stored;
         this.storeForFutureUse = storeForFutureUse;
+        this.billingAddress = billingAddress;
+        this.phone = phone;
         this.accountHolder = accountHolder;
+        this.allowUpdate = allowUpdate;
     }
 
     public RequestIdSource() {
diff --git a/src/main/java/com/checkout/payments/request/source/RequestNetworkTokenSource.java b/src/main/java/com/checkout/payments/request/source/RequestNetworkTokenSource.java
index 352c2968..e23ff339 100644
--- a/src/main/java/com/checkout/payments/request/source/RequestNetworkTokenSource.java
+++ b/src/main/java/com/checkout/payments/request/source/RequestNetworkTokenSource.java
@@ -4,7 +4,6 @@
 import com.checkout.common.Address;
 import com.checkout.common.Phone;
 import com.checkout.payments.NetworkTokenType;
-import com.google.gson.annotations.SerializedName;
 import lombok.Builder;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
@@ -19,36 +18,82 @@
 @ToString(callSuper = true)
 public final class RequestNetworkTokenSource extends AbstractRequestSource {
 
+    /**
+     * The network token value.
+     * [Optional]
+     */
     private String token;
 
-    @SerializedName("expiry_month")
+    /**
+     * The expiry month of the token.
+     * [Optional]
+     */
     private Integer expiryMonth;
 
-    @SerializedName("expiry_year")
+    /**
+     * The expiry year of the token.
+     * [Optional]
+     */
     private Integer expiryYear;
 
-    @SerializedName("token_type")
+    /**
+     * The network token type.
+     * [Optional]
+     */
     private NetworkTokenType tokenType;
 
+    /**
+     * The cryptogram for the network token (device pan). Required for Visa and Mastercard DPAN payments.
+     * [Optional]
+     */
     private String cryptogram;
 
+    /**
+     * The Electronic Commerce Indicator (ECI) security level.
+     * [Optional]
+     */
     private String eci;
 
+    /**
+     * Set to true for payments that use stored card details. Write-only.
+     * [Optional]
+     */
     private Boolean stored;
 
-    @SerializedName("store_for_future_use")
+    /**
+     * Set to true if you intend to reuse the payment credentials in subsequent payments. Write-only.
+     * [Optional]
+     */
     private Boolean storeForFutureUse;
 
+    /**
+     * The cardholder's name. Write-only.
+     * [Optional]
+     */
     private String name;
 
+    /**
+     * The card verification value/code. 3 digits, except for American Express (4 digits). Write-only.
+     * [Optional]
+     */
     private String cvv;
 
-    @SerializedName("billing_address")
+    /**
+     * The payment source owner's billing address.
+     * [Optional]
+     */
     private Address billingAddress;
 
+    /**
+     * The payment source owner's phone number.
+     * [Optional]
+     */
     private Phone phone;
 
-    @SerializedName("account_holder")
+    /**
+     * The card account holder's details.
+     * [Optional]
+     */
     private AccountHolder accountHolder;
 
     @Builder
diff --git a/src/main/java/com/checkout/payments/request/source/RequestProviderTokenSource.java b/src/main/java/com/checkout/payments/request/source/RequestProviderTokenSource.java
index dbb6c65f..25d8bc73 100644
--- a/src/main/java/com/checkout/payments/request/source/RequestProviderTokenSource.java
+++ b/src/main/java/com/checkout/payments/request/source/RequestProviderTokenSource.java
@@ -2,7 +2,6 @@
 
 import com.checkout.common.AccountHolder;
 import com.checkout.common.PaymentSourceType;
-import com.google.gson.annotations.SerializedName;
 import lombok.Builder;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
@@ -15,12 +14,22 @@
 @ToString(callSuper = true)
 public final class RequestProviderTokenSource extends AbstractRequestSource {
 
-    @SerializedName("payment_method")
+    /**
+     * The payment method to use.
+     * [Optional]
+     */
     private String paymentMethod;
 
+    /**
+     * The provider token value.
+     * [Optional]
+     */
     private String token;
 
-    @SerializedName("account_holder")
+    /**
+     * The account holder's details.
+     * [Optional]
+     */
     private AccountHolder accountHolder;
 
     @Builder
diff --git a/src/main/java/com/checkout/payments/request/source/RequestTokenSource.java b/src/main/java/com/checkout/payments/request/source/RequestTokenSource.java
index 07e10fba..45a2f698 100644
--- a/src/main/java/com/checkout/payments/request/source/RequestTokenSource.java
+++ b/src/main/java/com/checkout/payments/request/source/RequestTokenSource.java
@@ -4,7 +4,6 @@
 import com.checkout.common.Address;
 import com.checkout.common.PaymentSourceType;
 import com.checkout.common.Phone;
-import com.google.gson.annotations.SerializedName;
 import lombok.Builder;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
@@ -17,19 +16,40 @@
 @ToString(callSuper = true)
 public final class RequestTokenSource extends AbstractRequestSource {
 
+    /**
+     * The Checkout.com token value.
+     * [Optional]
+     */
     private String token;
 
-    @SerializedName("billing_address")
+    /**
+     * The payment source owner's billing address.
+     * [Optional]
+     */
     private Address billingAddress;
 
+    /**
+     * The payment source owner's phone number.
+     * [Optional]
+     */
     private Phone phone;
 
+    /**
+     * Set to true for payments that use stored card details. Write-only.
+     * [Optional]
+     */
     private Boolean stored;
 
-    @SerializedName("store_for_future_use")
+    /**
+     * Set to true if you intend to reuse the payment credentials in subsequent payments. Write-only.
+     * [Optional]
+     */
     private Boolean storeForFutureUse;
 
-    @SerializedName("account_holder")
+    /**
+     * The card account holder's details.
+     * [Optional]
+     */
     private AccountHolder accountHolder;
 
     @Builder
diff --git a/src/main/java/com/checkout/payments/request/source/apm/MandateType.java b/src/main/java/com/checkout/payments/request/source/apm/MandateType.java
new file mode 100644
index 00000000..08e89309
--- /dev/null
+++ b/src/main/java/com/checkout/payments/request/source/apm/MandateType.java
@@ -0,0 +1,13 @@
+package com.checkout.payments.request.source.apm;
+
+import com.google.gson.annotations.SerializedName;
+
+public enum MandateType {
+
+    @SerializedName("Core")
+    CORE,
+
+    @SerializedName("B2B")
+    B2B,
+
+}
diff --git a/src/main/java/com/checkout/payments/request/source/apm/RequestAchSource.java b/src/main/java/com/checkout/payments/request/source/apm/RequestAchSource.java
index 231975d5..10a68a15 100644
--- a/src/main/java/com/checkout/payments/request/source/apm/RequestAchSource.java
+++ b/src/main/java/com/checkout/payments/request/source/apm/RequestAchSource.java
@@ -5,7 +5,6 @@
 import com.checkout.common.CountryCode;
 import com.checkout.common.PaymentSourceType;
 import com.checkout.payments.request.source.AbstractRequestSource;
-import com.google.gson.annotations.SerializedName;
 import lombok.Builder;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
@@ -18,19 +17,39 @@
 @ToString(callSuper = true)
 public final class RequestAchSource extends AbstractRequestSource {
 
-    @SerializedName("account_type")
+    /**
+     * The type of Direct Debit account.
+     * [Required]
+     * Enum: "savings" "checking" "cash"
+     */
     private AccountType accountType;
 
-    @SerializedName("country")
+    /**
+     * The source country as an ISO 3166-1 alpha-2 code.
+     * [Required]
+     * min 2 characters, max 2 characters
+     */
     private CountryCode country;
 
-    @SerializedName("account_number")
+    /**
+     * The account number of the Direct Debit account.
+     * [Required]
+     * min 4 characters, max 17 characters
+     */
     private String accountNumber;
 
-    @SerializedName("bank_code")
+    /**
+     * The bank code (ABA routing number) of the Direct Debit account.
+     * [Required]
+     * min 8 characters, max 9 characters
+     */
     private String bankCode;
 
-    @SerializedName("account_holder")
+    /**
+     * The account holder's personal information.
+     * Supports date_of_birth and identification (SSN) fields.
+     * [Required]
+     */
     private AccountHolder accountHolder;
 
     @Builder
@@ -51,4 +70,4 @@ private RequestAchSource(
     public RequestAchSource() {
         super(PaymentSourceType.ACH);
     }
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/checkout/payments/request/source/apm/RequestAfterPaySource.java b/src/main/java/com/checkout/payments/request/source/apm/RequestAfterPaySource.java
index c49cfe7c..9edea45c 100644
--- a/src/main/java/com/checkout/payments/request/source/apm/RequestAfterPaySource.java
+++ b/src/main/java/com/checkout/payments/request/source/apm/RequestAfterPaySource.java
@@ -3,7 +3,6 @@
 import com.checkout.common.AccountHolder;
 import com.checkout.common.PaymentSourceType;
 import com.checkout.payments.request.source.AbstractRequestSource;
-import com.google.gson.annotations.SerializedName;
 import lombok.Builder;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
@@ -16,7 +15,10 @@
 @ToString(callSuper = true)
 public final class RequestAfterPaySource extends AbstractRequestSource {
 
-    @SerializedName("account_holder")
+    /**
+     * The account holder's details.
+     * [Optional]
+     */
     private AccountHolder accountHolder;
 
     @Builder
diff --git a/src/main/java/com/checkout/payments/request/source/apm/RequestAlmaSource.java b/src/main/java/com/checkout/payments/request/source/apm/RequestAlmaSource.java
index 2b58f2d3..06b6b728 100644
--- a/src/main/java/com/checkout/payments/request/source/apm/RequestAlmaSource.java
+++ b/src/main/java/com/checkout/payments/request/source/apm/RequestAlmaSource.java
@@ -3,7 +3,6 @@
 import com.checkout.common.Address;
 import com.checkout.common.PaymentSourceType;
 import com.checkout.payments.request.source.AbstractRequestSource;
-import com.google.gson.annotations.SerializedName;
 import lombok.Builder;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
@@ -16,7 +15,10 @@
 @ToString(callSuper = true)
 public final class RequestAlmaSource extends AbstractRequestSource {
 
-    @SerializedName("billing_address")
+    /**
+     * The customer's billing address.
+     * [Optional]
+     */
     private Address billingAddress;
 
     @Builder
diff --git a/src/main/java/com/checkout/payments/request/source/apm/RequestBancontactSource.java b/src/main/java/com/checkout/payments/request/source/apm/RequestBancontactSource.java
index f199a370..4e09d30c 100644
--- a/src/main/java/com/checkout/payments/request/source/apm/RequestBancontactSource.java
+++ b/src/main/java/com/checkout/payments/request/source/apm/RequestBancontactSource.java
@@ -3,7 +3,6 @@
 import com.checkout.common.CountryCode;
 import com.checkout.common.PaymentSourceType;
 import com.checkout.payments.request.source.AbstractRequestSource;
-import com.google.gson.annotations.SerializedName;
 import lombok.Builder;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
@@ -16,15 +15,29 @@
 @ToString(callSuper = true)
 public final class RequestBancontactSource extends AbstractRequestSource {
 
-    @SerializedName("payment_country")
+    /**
+     * The two-letter ISO country code of the payment.
+     * [Optional]
+     */
     private CountryCode paymentCountry;
 
-    @SerializedName("account_holder_name")
+    /**
+     * The account holder's name.
+     * [Optional]
+     * min 3 max 100
+     */
     private String accountHolderName;
 
-    @SerializedName("billing_descriptor")
+    /**
+     * A description of the purchase shown on the customer's statement.
+     * [Optional]
+     */
     private String billingDescriptor;
 
+    /**
+     * The language to display the payment page in.
+     * [Optional]
+     */
     private String language;
 
     @Builder
diff --git a/src/main/java/com/checkout/payments/request/source/apm/RequestBizumSource.java b/src/main/java/com/checkout/payments/request/source/apm/RequestBizumSource.java
index eeae284e..180f0052 100644
--- a/src/main/java/com/checkout/payments/request/source/apm/RequestBizumSource.java
+++ b/src/main/java/com/checkout/payments/request/source/apm/RequestBizumSource.java
@@ -2,7 +2,6 @@
 
 import com.checkout.common.PaymentSourceType;
 import com.checkout.payments.request.source.AbstractRequestSource;
-import com.google.gson.annotations.SerializedName;
 import lombok.Builder;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
@@ -15,7 +14,12 @@
 @ToString(callSuper = true)
 public final class RequestBizumSource extends AbstractRequestSource {
 
-    @SerializedName("mobile_number")
+    /**
+     * The customer's mobile number.
+     * [Optional]
+     * @deprecated Removed from the API on 2025/02/10. Use the customer object instead.
+     */
+    @Deprecated
     private String mobileNumber;
 
     @Builder
@@ -27,4 +31,4 @@ private RequestBizumSource(final String mobileNumber) {
     public RequestBizumSource() {
         super(PaymentSourceType.BIZUM);
     }
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/checkout/payments/request/source/apm/RequestCvConnectSource.java b/src/main/java/com/checkout/payments/request/source/apm/RequestCvConnectSource.java
index 4c16b194..c2481d80 100644
--- a/src/main/java/com/checkout/payments/request/source/apm/RequestCvConnectSource.java
+++ b/src/main/java/com/checkout/payments/request/source/apm/RequestCvConnectSource.java
@@ -3,7 +3,6 @@
 import com.checkout.common.Address;
 import com.checkout.common.PaymentSourceType;
 import com.checkout.payments.request.source.AbstractRequestSource;
-import com.google.gson.annotations.SerializedName;
 import lombok.Builder;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
@@ -16,7 +15,10 @@
 @ToString(callSuper = true)
 public final class RequestCvConnectSource extends AbstractRequestSource {
 
-    @SerializedName("billing_address")
+    /**
+     * The customer's billing address.
+     * [Optional]
+     */
     private Address billingAddress;
 
     @Builder
diff --git a/src/main/java/com/checkout/payments/request/source/apm/RequestEpsSource.java b/src/main/java/com/checkout/payments/request/source/apm/RequestEpsSource.java
index e838fab3..69fb81c6 100644
--- a/src/main/java/com/checkout/payments/request/source/apm/RequestEpsSource.java
+++ b/src/main/java/com/checkout/payments/request/source/apm/RequestEpsSource.java
@@ -3,7 +3,6 @@
 import com.checkout.common.AccountHolder;
 import com.checkout.common.PaymentSourceType;
 import com.checkout.payments.request.source.AbstractRequestSource;
-import com.google.gson.annotations.SerializedName;
 import lombok.Builder;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
@@ -16,9 +15,16 @@
 @ToString(callSuper = true)
 public final class RequestEpsSource extends AbstractRequestSource {
 
+    /**
+     * The purpose of the payment.
+     * [Optional]
+     */
     private String purpose;
 
-    @SerializedName("account_holder")
+    /**
+     * The account holder's details.
+     * [Optional]
+     */
     private AccountHolder accountHolder;
 
     @Builder
diff --git a/src/main/java/com/checkout/payments/request/source/apm/RequestFawrySource.java b/src/main/java/com/checkout/payments/request/source/apm/RequestFawrySource.java
index a2cb0b09..5a9e44c1 100644
--- a/src/main/java/com/checkout/payments/request/source/apm/RequestFawrySource.java
+++ b/src/main/java/com/checkout/payments/request/source/apm/RequestFawrySource.java
@@ -21,20 +21,41 @@
 @ToString(callSuper = true)
 public final class RequestFawrySource extends AbstractRequestSource {
 
+    /**
+     * The description of the payment.
+     * [Optional]
+     */
     private String description;
 
-    @SerializedName("customer_profile_id")
+    /**
+     * The customer's profile ID.
+     * [Optional]
+     */
     private String customerProfileId;
 
-    @SerializedName("customer_email")
+    /**
+     * The customer's email address.
+     * [Optional]
+     */
     private String customerEmail;
 
-    @SerializedName("customer_mobile")
+    /**
+     * The customer's mobile number.
+     * [Optional]
+     */
     private String customerMobile;
 
-    @SerializedName("expires_on")
+    /**
+     * The timestamp after which the payment expires.
+     * [Optional]
+     * Format: date-time (ISO 8601)
+     */
     private Instant expiresOn;
 
+    /**
+     * The products included in the order.
+     * [Optional]
+     */
     private List<Product> products;
 
     @Builder
@@ -63,15 +84,31 @@ public RequestFawrySource() {
     @AllArgsConstructor
     public static class Product {
 
+        /**
+         * The product identifier.
+         * [Optional]
+         */
         @SerializedName("product_id")
         private String id;
 
+        /**
+         * The quantity of the product.
+         * [Optional]
+         */
         private Long quantity;
 
+        /**
+         * The price of the product in minor currency units.
+         * [Optional]
+         */
         private Long price;
 
+        /**
+         * The description of the product.
+         * [Optional]
+         */
         private String description;
 
     }
 
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/checkout/payments/request/source/apm/RequestGiropaySource.java b/src/main/java/com/checkout/payments/request/source/apm/RequestGiropaySource.java
index 3378d909..aabaeaec 100644
--- a/src/main/java/com/checkout/payments/request/source/apm/RequestGiropaySource.java
+++ b/src/main/java/com/checkout/payments/request/source/apm/RequestGiropaySource.java
@@ -3,7 +3,6 @@
 import com.checkout.common.AccountHolder;
 import com.checkout.common.PaymentSourceType;
 import com.checkout.payments.request.source.AbstractRequestSource;
-import com.google.gson.annotations.SerializedName;
 import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Data;
@@ -22,19 +21,25 @@
 public final class RequestGiropaySource extends AbstractRequestSource {
 
     /**
+     * The purpose of the payment.
+     * [Optional]
      * @deprecated GiroPay doesn't support this field anymore, will be removed in the future
      */
     @Deprecated
     private String purpose;
 
     /**
+     * Additional information fields for the payment.
+     * [Optional]
      * @deprecated GiroPay doesn't support this field anymore, will be removed in the future
      */
     @Deprecated
-    @SerializedName("info_fields")
     private List<InfoFields> infoFields;
 
-    @SerializedName("account_holder")
+    /**
+     * The account holder's details.
+     * [Optional]
+     */
     private AccountHolder accountHolder;
 
     @Builder
@@ -56,7 +61,17 @@ public RequestGiropaySource() {
     @NoArgsConstructor
     @AllArgsConstructor
     public static class InfoFields {
+
+        /**
+         * The label for the information field.
+         * [Optional]
+         */
         private String label;
+
+        /**
+         * The text content of the information field.
+         * [Optional]
+         */
         private String text;
     }
 
diff --git a/src/main/java/com/checkout/payments/request/source/apm/RequestIdealSource.java b/src/main/java/com/checkout/payments/request/source/apm/RequestIdealSource.java
index 69473f41..6427c50b 100644
--- a/src/main/java/com/checkout/payments/request/source/apm/RequestIdealSource.java
+++ b/src/main/java/com/checkout/payments/request/source/apm/RequestIdealSource.java
@@ -14,8 +14,17 @@
 @ToString(callSuper = true)
 public final class RequestIdealSource extends AbstractRequestSource {
 
+    /**
+     * A description of the payment shown to the customer.
+     * [Optional]
+     * max 35 characters
+     */
     private String description;
 
+    /**
+     * The language to display the payment page in.
+     * [Optional]
+     */
     private String language;
 
     @Builder
diff --git a/src/main/java/com/checkout/payments/request/source/apm/RequestIllicadoSource.java b/src/main/java/com/checkout/payments/request/source/apm/RequestIllicadoSource.java
index ab836d78..c41cbde1 100644
--- a/src/main/java/com/checkout/payments/request/source/apm/RequestIllicadoSource.java
+++ b/src/main/java/com/checkout/payments/request/source/apm/RequestIllicadoSource.java
@@ -11,6 +11,10 @@
 @ToString(callSuper = true)
 public final class RequestIllicadoSource extends AbstractRequestSource {
 
+    /**
+     * The customer's billing address.
+     * [Optional]
+     */
     private Address billingAddress;
 
     @Builder
diff --git a/src/main/java/com/checkout/payments/request/source/apm/RequestKlarnaSource.java b/src/main/java/com/checkout/payments/request/source/apm/RequestKlarnaSource.java
index fe2cc1e9..2ffd7f97 100644
--- a/src/main/java/com/checkout/payments/request/source/apm/RequestKlarnaSource.java
+++ b/src/main/java/com/checkout/payments/request/source/apm/RequestKlarnaSource.java
@@ -3,7 +3,6 @@
 import com.checkout.common.AccountHolder;
 import com.checkout.common.PaymentSourceType;
 import com.checkout.payments.request.source.AbstractRequestSource;
-import com.google.gson.annotations.SerializedName;
 import lombok.Builder;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
@@ -16,15 +15,16 @@
 @ToString(callSuper = true)
 public final class RequestKlarnaSource extends AbstractRequestSource {
 
-    @SerializedName("account_holder")
+    /**
+     * The account holder's details.
+     * [Optional]
+     */
     private AccountHolder accountHolder;
 
-
     @Builder
     private RequestKlarnaSource(final AccountHolder accountHolder) {
         super(PaymentSourceType.KLARNA);
         this.accountHolder = accountHolder;
-
     }
 
     public RequestKlarnaSource() {
diff --git a/src/main/java/com/checkout/payments/request/source/apm/RequestKnetSource.java b/src/main/java/com/checkout/payments/request/source/apm/RequestKnetSource.java
index fd6efb9a..b0e06813 100644
--- a/src/main/java/com/checkout/payments/request/source/apm/RequestKnetSource.java
+++ b/src/main/java/com/checkout/payments/request/source/apm/RequestKnetSource.java
@@ -4,7 +4,6 @@
 import com.checkout.payments.PaymentMethodDetails;
 import com.checkout.payments.request.source.AbstractRequestSource;
 import com.checkout.tokens.ApplePayTokenData;
-import com.google.gson.annotations.SerializedName;
 import lombok.Builder;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
@@ -17,35 +16,70 @@
 @ToString(callSuper = true)
 public final class RequestKnetSource extends AbstractRequestSource {
 
+    /**
+     * The language to display the payment page in.
+     * [Optional]
+     */
     private String language;
 
-    @SerializedName("user_defined_field1")
+    /**
+     * User-defined field 1.
+     * [Optional]
+     */
     private String userDefinedField1;
 
-    @SerializedName("user_defined_field2")
+    /**
+     * User-defined field 2.
+     * [Optional]
+     */
     private String userDefinedField2;
 
-    @SerializedName("user_defined_field3")
+    /**
+     * User-defined field 3.
+     * [Optional]
+     */
     private String userDefinedField3;
 
-    @SerializedName("user_defined_field4")
+    /**
+     * User-defined field 4.
+     * [Optional]
+     */
     private String userDefinedField4;
 
-    @SerializedName("user_defined_field5")
+    /**
+     * User-defined field 5.
+     * [Optional]
+     */
     private String userDefinedField5;
 
-    @SerializedName("card_token")
+    /**
+     * The card token for the payment.
+     * [Optional]
+     */
     private String cardToken;
 
+    /**
+     * The PTLF value.
+     * [Optional]
+     */
     private String ptlf;
 
-    @SerializedName("token_type")
+    /**
+     * The type of token.
+     * [Optional]
+     */
     private String tokenType;
 
-    @SerializedName("token_data")
+    /**
+     * The token data for Apple Pay payments.
+     * [Optional]
+     */
     private ApplePayTokenData tokenData;
 
-    @SerializedName("payment_method_details")
+    /**
+     * Additional payment method details.
+     * [Optional]
+     */
     private PaymentMethodDetails paymentMethodDetails;
 
     @Builder
diff --git a/src/main/java/com/checkout/payments/request/source/apm/RequestMultiBancoSource.java b/src/main/java/com/checkout/payments/request/source/apm/RequestMultiBancoSource.java
index f5fc127d..498ac7ab 100644
--- a/src/main/java/com/checkout/payments/request/source/apm/RequestMultiBancoSource.java
+++ b/src/main/java/com/checkout/payments/request/source/apm/RequestMultiBancoSource.java
@@ -3,7 +3,6 @@
 import com.checkout.common.CountryCode;
 import com.checkout.common.PaymentSourceType;
 import com.checkout.payments.request.source.AbstractRequestSource;
-import com.google.gson.annotations.SerializedName;
 import lombok.Builder;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
@@ -16,13 +15,23 @@
 @ToString(callSuper = true)
 public final class RequestMultiBancoSource extends AbstractRequestSource {
 
-    @SerializedName("payment_country")
+    /**
+     * The two-letter ISO country code of the payment.
+     * [Optional]
+     */
     private CountryCode paymentCountry;
 
-    @SerializedName("account_holder_name")
+    /**
+     * The account holder's name.
+     * [Optional]
+     * min 3 max 100
+     */
     private String accountHolderName;
 
-    @SerializedName("billing_descriptor")
+    /**
+     * A description of the purchase shown on the customer's statement.
+     * [Optional]
+     */
     private String billingDescriptor;
 
     @Builder
diff --git a/src/main/java/com/checkout/payments/request/source/apm/RequestP24Source.java b/src/main/java/com/checkout/payments/request/source/apm/RequestP24Source.java
index 0216afb0..1feadf0b 100644
--- a/src/main/java/com/checkout/payments/request/source/apm/RequestP24Source.java
+++ b/src/main/java/com/checkout/payments/request/source/apm/RequestP24Source.java
@@ -3,7 +3,6 @@
 import com.checkout.common.CountryCode;
 import com.checkout.common.PaymentSourceType;
 import com.checkout.payments.request.source.AbstractRequestSource;
-import com.google.gson.annotations.SerializedName;
 import lombok.Builder;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
@@ -16,16 +15,29 @@
 @ToString(callSuper = true)
 public final class RequestP24Source extends AbstractRequestSource {
 
-    @SerializedName("payment_country")
+    /**
+     * The two-letter ISO country code of the payment.
+     * [Optional]
+     */
     private CountryCode paymentCountry;
 
-    @SerializedName("account_holder_name")
+    /**
+     * The account holder's name.
+     * [Optional]
+     * min 3 max 100
+     */
     private String accountHolderName;
 
-    @SerializedName("account_holder_email")
+    /**
+     * The account holder's email address.
+     * [Optional]
+     */
     private String accountHolderEmail;
 
-    @SerializedName("billing_descriptor")
+    /**
+     * A description of the purchase shown on the customer's statement.
+     * [Optional]
+     */
     private String billingDescriptor;
 
     @Builder
diff --git a/src/main/java/com/checkout/payments/request/source/apm/RequestPayPalSource.java b/src/main/java/com/checkout/payments/request/source/apm/RequestPayPalSource.java
index 3d1d2a41..ceec52c7 100644
--- a/src/main/java/com/checkout/payments/request/source/apm/RequestPayPalSource.java
+++ b/src/main/java/com/checkout/payments/request/source/apm/RequestPayPalSource.java
@@ -15,6 +15,10 @@
 @ToString(callSuper = true)
 public final class RequestPayPalSource extends AbstractRequestSource {
 
+    /**
+     * The billing plan details for recurring PayPal payments.
+     * [Optional]
+     */
     private BillingPlan plan;
 
     @Builder
diff --git a/src/main/java/com/checkout/payments/request/source/apm/RequestPlaidSource.java b/src/main/java/com/checkout/payments/request/source/apm/RequestPlaidSource.java
index 730d1537..4c03c49c 100644
--- a/src/main/java/com/checkout/payments/request/source/apm/RequestPlaidSource.java
+++ b/src/main/java/com/checkout/payments/request/source/apm/RequestPlaidSource.java
@@ -3,7 +3,6 @@
 import com.checkout.common.AccountHolder;
 import com.checkout.common.PaymentSourceType;
 import com.checkout.payments.request.source.AbstractRequestSource;
-import com.google.gson.annotations.SerializedName;
 import lombok.Builder;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
@@ -16,10 +15,16 @@
 @ToString(callSuper = true)
 public final class RequestPlaidSource extends AbstractRequestSource {
 
-    @SerializedName("token")
+    /**
+     * The Plaid processor token.
+     * [Optional]
+     */
     private String token;
 
-    @SerializedName("account_holder")
+    /**
+     * The account holder's details.
+     * [Optional]
+     */
     private AccountHolder accountHolder;
 
     @Builder
@@ -32,4 +37,4 @@ private RequestPlaidSource(final String token, final AccountHolder accountHolder
     public RequestPlaidSource() {
         super(PaymentSourceType.PLAID);
     }
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/checkout/payments/request/source/apm/RequestPostFinanceSource.java b/src/main/java/com/checkout/payments/request/source/apm/RequestPostFinanceSource.java
index 99400a20..eb4be737 100644
--- a/src/main/java/com/checkout/payments/request/source/apm/RequestPostFinanceSource.java
+++ b/src/main/java/com/checkout/payments/request/source/apm/RequestPostFinanceSource.java
@@ -3,7 +3,6 @@
 import com.checkout.common.CountryCode;
 import com.checkout.common.PaymentSourceType;
 import com.checkout.payments.request.source.AbstractRequestSource;
-import com.google.gson.annotations.SerializedName;
 import lombok.Builder;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
@@ -16,13 +15,22 @@
 @ToString(callSuper = true)
 public final class RequestPostFinanceSource extends AbstractRequestSource {
 
-    @SerializedName("payment_country")
+    /**
+     * The two-letter ISO country code of the payment.
+     * [Optional]
+     */
     private CountryCode paymentCountry;
 
-    @SerializedName("account_holder_name")
+    /**
+     * The account holder's name.
+     * [Optional]
+     */
     private String accountHolderName;
 
-    @SerializedName("billing_descriptor")
+    /**
+     * A description of the purchase shown on the customer's statement.
+     * [Optional]
+     */
     private String billingDescriptor;
 
     @Builder
diff --git a/src/main/java/com/checkout/payments/request/source/apm/RequestQPaySource.java b/src/main/java/com/checkout/payments/request/source/apm/RequestQPaySource.java
index 990c34ba..78ecf1d0 100644
--- a/src/main/java/com/checkout/payments/request/source/apm/RequestQPaySource.java
+++ b/src/main/java/com/checkout/payments/request/source/apm/RequestQPaySource.java
@@ -2,7 +2,6 @@
 
 import com.checkout.common.PaymentSourceType;
 import com.checkout.payments.request.source.AbstractRequestSource;
-import com.google.gson.annotations.SerializedName;
 import lombok.Builder;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
@@ -15,13 +14,29 @@
 @ToString(callSuper = true)
 public final class RequestQPaySource extends AbstractRequestSource {
 
+    /**
+     * The number of items in the order.
+     * [Optional]
+     */
     private Integer quantity;
 
+    /**
+     * A description of the payment.
+     * [Optional]
+     * max 255
+     */
     private String description;
 
+    /**
+     * The language to display the payment page in.
+     * [Optional]
+     */
     private String language;
 
-    @SerializedName("national_id")
+    /**
+     * The customer's national ID.
+     * [Optional]
+     */
     private String nationalId;
 
     @Builder
diff --git a/src/main/java/com/checkout/payments/request/source/apm/RequestSepaSource.java b/src/main/java/com/checkout/payments/request/source/apm/RequestSepaSource.java
index 13bbd611..ec86cf4f 100644
--- a/src/main/java/com/checkout/payments/request/source/apm/RequestSepaSource.java
+++ b/src/main/java/com/checkout/payments/request/source/apm/RequestSepaSource.java
@@ -1,9 +1,15 @@
 package com.checkout.payments.request.source.apm;
 
-import com.checkout.common.*;
+import com.checkout.common.AccountHolder;
+import com.checkout.common.CountryCode;
+import com.checkout.common.Currency;
+import com.checkout.common.PaymentSourceType;
 import com.checkout.payments.request.source.AbstractRequestSource;
-import com.google.gson.annotations.SerializedName;
-import lombok.*;
+import lombok.Builder;
+import lombok.EqualsAndHashCode;
+import lombok.Getter;
+import lombok.Setter;
+import lombok.ToString;
 
 @Getter
 @Setter
@@ -11,23 +17,53 @@
 @ToString(callSuper = true)
 public final class RequestSepaSource extends AbstractRequestSource {
 
+    /**
+     * The account's country, as an ISO 3166-1 alpha-2 code.
+     * [Required]
+     */
     private CountryCode country;
 
-    @SerializedName("account_number")
+    /**
+     * The account holder's IBAN.
+     * [Required]
+     */
     private String accountNumber;
 
-    @SerializedName("bank_code")
+    /**
+     * The BIC/SWIFT code of the bank.
+     * [Optional]
+     */
     private String bankCode;
 
+    /**
+     * The account holder's account currency.
+     * [Required]
+     */
     private Currency currency;
 
-    @SerializedName("mandate_id")
+    /**
+     * The ID of the mandate.
+     * [Optional]
+     */
     private String mandateId;
 
-    @SerializedName("date_of_signature")
+    /**
+     * The type of mandate.
+     * [Optional]
+     * Enum: "Core" "B2B"
+     */
+    private MandateType mandateType;
+
+    /**
+     * The date the mandate was signed, in the format yyyy-MM-dd.
+     * [Optional]
+     */
     private String dateOfSignature;
 
-    @SerializedName("account_holder")
+    /**
+     * The account holder's personal information.
+     * [Required]
+     */
     private AccountHolder accountHolder;
 
     @Builder
@@ -37,6 +73,7 @@ private RequestSepaSource(
             final String bankCode,
             final Currency currency,
             final String mandateId,
+            final MandateType mandateType,
             final String dateOfSignature,
             final AccountHolder accountHolder
     ) {
@@ -46,6 +83,7 @@ private RequestSepaSource(
         this.bankCode = bankCode;
         this.currency = currency;
         this.mandateId = mandateId;
+        this.mandateType = mandateType;
         this.dateOfSignature = dateOfSignature;
         this.accountHolder = accountHolder;
     }
diff --git a/src/main/java/com/checkout/payments/request/source/apm/RequestSequraSource.java b/src/main/java/com/checkout/payments/request/source/apm/RequestSequraSource.java
index fa2d3431..295d0e27 100644
--- a/src/main/java/com/checkout/payments/request/source/apm/RequestSequraSource.java
+++ b/src/main/java/com/checkout/payments/request/source/apm/RequestSequraSource.java
@@ -3,7 +3,6 @@
 import com.checkout.common.Address;
 import com.checkout.common.PaymentSourceType;
 import com.checkout.payments.request.source.AbstractRequestSource;
-import com.google.gson.annotations.SerializedName;
 import lombok.Builder;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
@@ -16,7 +15,10 @@
 @ToString(callSuper = true)
 public final class RequestSequraSource extends AbstractRequestSource {
 
-    @SerializedName("billing_address")
+    /**
+     * The customer's billing address.
+     * [Optional]
+     */
     private Address billingAddress;
 
     @Builder
@@ -28,4 +30,4 @@ private RequestSequraSource(final Address billingAddress) {
     public RequestSequraSource() {
         super(PaymentSourceType.SEQURA);
     }
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/checkout/payments/request/source/apm/RequestSofortSource.java b/src/main/java/com/checkout/payments/request/source/apm/RequestSofortSource.java
index 177a7581..028b5aa7 100644
--- a/src/main/java/com/checkout/payments/request/source/apm/RequestSofortSource.java
+++ b/src/main/java/com/checkout/payments/request/source/apm/RequestSofortSource.java
@@ -3,23 +3,32 @@
 import com.checkout.common.CountryCode;
 import com.checkout.common.PaymentSourceType;
 import com.checkout.payments.request.source.AbstractRequestSource;
-import com.google.gson.annotations.SerializedName;
 import lombok.Builder;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
 import lombok.Setter;
 import lombok.ToString;
 
+/**
+ * @deprecated Sofort was deprecated as a payment source type on 2024/12/03.
+ */
+@Deprecated
 @Getter
 @Setter
 @EqualsAndHashCode(callSuper = true)
 @ToString(callSuper = true)
 public final class RequestSofortSource extends AbstractRequestSource {
 
-    @SerializedName("countryCode")
+    /**
+     * The ISO 3166-1 alpha-2 country code for the Sofort payment.
+     * [Optional]
+     */
     private CountryCode countryCode;
 
-    @SerializedName("languageCode")
+    /**
+     * The language code for the Sofort payment.
+     * [Optional]
+     */
     private String languageCode;
 
     @Builder
@@ -29,6 +38,7 @@ private RequestSofortSource(final CountryCode countryCode, final String language
         this.languageCode = languageCode;
     }
 
+    @Deprecated
     public RequestSofortSource() {
         super(PaymentSourceType.SOFORT);
     }
diff --git a/src/main/java/com/checkout/payments/request/source/apm/RequestSwishSource.java b/src/main/java/com/checkout/payments/request/source/apm/RequestSwishSource.java
index 5a7a11f1..46813b62 100644
--- a/src/main/java/com/checkout/payments/request/source/apm/RequestSwishSource.java
+++ b/src/main/java/com/checkout/payments/request/source/apm/RequestSwishSource.java
@@ -4,7 +4,6 @@
 import com.checkout.common.PaymentSourceType;
 import com.checkout.payments.BillingDescriptor;
 import com.checkout.payments.request.source.AbstractRequestSource;
-import com.google.gson.annotations.SerializedName;
 import lombok.Builder;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
@@ -17,13 +16,22 @@
 @ToString(callSuper = true)
 public final class RequestSwishSource extends AbstractRequestSource {
 
-    @SerializedName("payment_country")
+    /**
+     * The two-letter ISO country code of the payment.
+     * [Optional]
+     */
     private String paymentCountry;
 
-    @SerializedName("account_holder")
+    /**
+     * The account holder's details.
+     * [Optional]
+     */
     private AccountHolder accountHolder;
 
-    @SerializedName("billing_descriptor")
+    /**
+     * A description of the purchase shown on the customer's statement.
+     * [Optional]
+     */
     private BillingDescriptor billingDescriptor;
 
     @Builder
diff --git a/src/main/java/com/checkout/payments/request/source/apm/RequestTamaraSource.java b/src/main/java/com/checkout/payments/request/source/apm/RequestTamaraSource.java
index e8b2a283..a73029ab 100644
--- a/src/main/java/com/checkout/payments/request/source/apm/RequestTamaraSource.java
+++ b/src/main/java/com/checkout/payments/request/source/apm/RequestTamaraSource.java
@@ -3,7 +3,6 @@
 import com.checkout.common.Address;
 import com.checkout.common.PaymentSourceType;
 import com.checkout.payments.request.source.AbstractRequestSource;
-import com.google.gson.annotations.SerializedName;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
 import lombok.Setter;
@@ -19,7 +18,10 @@ public RequestTamaraSource() {
         super(PaymentSourceType.TAMARA);
     }
 
-    @SerializedName("billing_address")
+    /**
+     * The customer's billing address.
+     * [Optional]
+     */
     private Address billingAddress;
 
 }
diff --git a/src/main/java/com/checkout/payments/request/source/apm/RequestTrustlySource.java b/src/main/java/com/checkout/payments/request/source/apm/RequestTrustlySource.java
index b1ca8177..9cd9350d 100644
--- a/src/main/java/com/checkout/payments/request/source/apm/RequestTrustlySource.java
+++ b/src/main/java/com/checkout/payments/request/source/apm/RequestTrustlySource.java
@@ -3,20 +3,26 @@
 import com.checkout.common.Address;
 import com.checkout.common.PaymentSourceType;
 import com.checkout.payments.request.source.AbstractRequestSource;
-import com.google.gson.annotations.SerializedName;
 import lombok.Builder;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
 import lombok.Setter;
 import lombok.ToString;
 
+/**
+ * @deprecated Trustly was removed as a payment method on 2024/09/17.
+ */
+@Deprecated
 @Getter
 @Setter
 @EqualsAndHashCode(callSuper = true)
 @ToString(callSuper = true)
 public final class RequestTrustlySource extends AbstractRequestSource {
 
-    @SerializedName("billing_address")
+    /**
+     * The billing address for the Trustly payment.
+     * [Optional]
+     */
     private Address billingAddress;
 
     @Builder
@@ -25,6 +31,7 @@ private RequestTrustlySource(final Address billingAddress) {
         this.billingAddress = billingAddress;
     }
 
+    @Deprecated
     public RequestTrustlySource() {
         super(PaymentSourceType.TRUSTLY);
     }
diff --git a/src/main/java/com/checkout/payments/request/source/apm/RequestWeChatPaySource.java b/src/main/java/com/checkout/payments/request/source/apm/RequestWeChatPaySource.java
index f00211d3..245496be 100644
--- a/src/main/java/com/checkout/payments/request/source/apm/RequestWeChatPaySource.java
+++ b/src/main/java/com/checkout/payments/request/source/apm/RequestWeChatPaySource.java
@@ -3,7 +3,6 @@
 import com.checkout.common.Address;
 import com.checkout.common.PaymentSourceType;
 import com.checkout.payments.request.source.AbstractRequestSource;
-import com.google.gson.annotations.SerializedName;
 import lombok.Builder;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
@@ -16,7 +15,10 @@
 @EqualsAndHashCode(callSuper = true)
 public final class RequestWeChatPaySource extends AbstractRequestSource {
 
-    @SerializedName("billing_address")
+    /**
+     * The customer's billing address.
+     * [Optional]
+     */
     private Address billingAddress;
 
     public RequestWeChatPaySource() {
diff --git a/src/main/java/com/checkout/payments/response/source/PayPalResponseSource.java b/src/main/java/com/checkout/payments/response/source/PayPalResponseSource.java
new file mode 100644
index 00000000..cc6a4e13
--- /dev/null
+++ b/src/main/java/com/checkout/payments/response/source/PayPalResponseSource.java
@@ -0,0 +1,41 @@
+package com.checkout.payments.response.source;
+
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+import lombok.ToString;
+
+import static com.checkout.common.PaymentSourceType.PAYPAL;
+
+@Data
+@EqualsAndHashCode(callSuper = true)
+@ToString(callSuper = true)
+public final class PayPalResponseSource extends AbstractResponseSource implements ResponseSource {
+
+    /**
+     * The PayPal account holder details.
+     * [Optional]
+     */
+    private AccountHolder accountHolder;
+
+    public PayPalResponseSource() {
+        this.type = PAYPAL;
+    }
+
+    @Data
+    public static final class AccountHolder {
+
+        /**
+         * The PayPal account holder's email address.
+         * [Optional]
+         */
+        private String email;
+
+        /**
+         * The PayPal account holder's full name.
+         * [Optional]
+         */
+        private String fullName;
+
+    }
+
+}
diff --git a/src/main/java/com/checkout/payments/sender/PaymentIndividualSender.java b/src/main/java/com/checkout/payments/sender/PaymentIndividualSender.java
index 0f3bdc02..37fcc9ca 100644
--- a/src/main/java/com/checkout/payments/sender/PaymentIndividualSender.java
+++ b/src/main/java/com/checkout/payments/sender/PaymentIndividualSender.java
@@ -22,28 +22,24 @@ public final class PaymentIndividualSender extends PaymentSender {
      * The sender's first name.
      * [Required]
      */
-    @SerializedName("first_name")
     private String firstName;
 
     /**
      * The sender's middle name.
      * [Optional]
      */
-    @SerializedName("middle_name")
     private String middleName;
 
     /**
      * The sender's last name.
      * [Required]
      */
-    @SerializedName("last_name")
     private String lastName;
 
     /**
-     * The sender's date of birth.
-     * [Optional]
-     * Format: yyyy-MM-dd
+     * @deprecated Renamed to {@link #dateOfBirth} (date_of_birth) per API changelog 2025/02/21.
      */
+    @Deprecated
     @SerializedName("dob")
     private String dob;
 
@@ -63,30 +59,26 @@ public final class PaymentIndividualSender extends PaymentSender {
      * The reference type for the sender.
      * [Optional]
      */
-    @SerializedName("reference_type")
     private String referenceType;
 
     /**
      * The source of funds for the sender.
      * [Optional]
      */
-    @SerializedName("source_of_funds")
     private SourceOfFunds sourceOfFunds;
 
     /**
-     * The sender's date of birth (yyyy-MM-dd).
+     * The sender's date of birth.
      * [Optional]
      * Format: yyyy-MM-dd
-     * &lt;= 10 characters
+     * max 10 characters
      */
-    @SerializedName("date_of_birth")
     private LocalDate dateOfBirth;
 
     /**
      * The sender's country of birth.
      * [Optional]
      */
-    @SerializedName("country_of_birth")
     private CountryCode countryOfBirth;
 
     /**
diff --git a/src/test/java/com/checkout/instruments/CreateInstrumentSepaRequestSerializationTest.java b/src/test/java/com/checkout/instruments/CreateInstrumentSepaRequestSerializationTest.java
new file mode 100644
index 00000000..01941859
--- /dev/null
+++ b/src/test/java/com/checkout/instruments/CreateInstrumentSepaRequestSerializationTest.java
@@ -0,0 +1,194 @@
+package com.checkout.instruments;
+
+import com.checkout.GsonSerializer;
+import com.checkout.common.AccountHolder;
+import com.checkout.common.Address;
+import com.checkout.common.CountryCode;
+import com.checkout.common.Currency;
+import com.checkout.instruments.create.CreateCustomerInstrumentRequest;
+import com.checkout.instruments.create.CreateInstrumentSepaRequest;
+import com.checkout.instruments.create.InstrumentData;
+import com.checkout.payments.PaymentType;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class CreateInstrumentSepaRequestSerializationTest {
+
+    private final GsonSerializer serializer = new GsonSerializer();
+
+    @Test
+    void shouldSerializeTypeAsSepa() {
+        final CreateInstrumentSepaRequest request = CreateInstrumentSepaRequest.builder()
+                .instrumentData(InstrumentData.builder()
+                        .accoountNumber("FR7630006000011234567890189")
+                        .country(CountryCode.FR)
+                        .currency(Currency.EUR)
+                        .build())
+                .accountHolder(AccountHolder.builder()
+                        .firstName("Jane")
+                        .lastName("Smith")
+                        .build())
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertNotNull(json);
+        assertTrue(json.contains("\"type\":\"sepa\""));
+    }
+
+    @Test
+    void shouldSerializeInstrumentData() {
+        final CreateInstrumentSepaRequest request = CreateInstrumentSepaRequest.builder()
+                .instrumentData(InstrumentData.builder()
+                        .accoountNumber("DE89370400440532013000")
+                        .country(CountryCode.DE)
+                        .currency(Currency.EUR)
+                        .paymentType(PaymentType.RECURRING)
+                        .build())
+                .accountHolder(AccountHolder.builder()
+                        .firstName("Hans")
+                        .lastName("Muller")
+                        .build())
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertTrue(json.contains("\"instrument_data\""));
+        assertTrue(json.contains("\"account_number\":\"DE89370400440532013000\""));
+        assertTrue(json.contains("\"country\":\"DE\""));
+        assertTrue(json.contains("\"currency\":\"EUR\""));
+    }
+
+    @Test
+    void shouldSerializeAccountHolder() {
+        final CreateInstrumentSepaRequest request = CreateInstrumentSepaRequest.builder()
+                .instrumentData(InstrumentData.builder().build())
+                .accountHolder(AccountHolder.builder()
+                        .firstName("Marie")
+                        .lastName("Dupont")
+                        .billingAddress(Address.builder()
+                                .addressLine1("10 Rue de la Paix")
+                                .city("Paris")
+                                .country(CountryCode.FR)
+                                .build())
+                        .build())
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertTrue(json.contains("\"account_holder\""));
+        assertTrue(json.contains("\"first_name\":\"Marie\""));
+        assertTrue(json.contains("\"last_name\":\"Dupont\""));
+        assertTrue(json.contains("\"billing_address\""));
+    }
+
+    @Test
+    void shouldSerializeOptionalCustomer() {
+        final CreateInstrumentSepaRequest request = CreateInstrumentSepaRequest.builder()
+                .instrumentData(InstrumentData.builder().build())
+                .accountHolder(AccountHolder.builder().build())
+                .customer(CreateCustomerInstrumentRequest.builder()
+                        .email("customer@example.com")
+                        .name("Jane Smith")
+                        .build())
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertTrue(json.contains("\"customer\""));
+        assertTrue(json.contains("\"email\":\"customer@example.com\""));
+        assertTrue(json.contains("\"name\":\"Jane Smith\""));
+    }
+
+    @Test
+    void shouldDeserializeInstrumentData() {
+        final String json = "{"
+                + "\"type\":\"sepa\","
+                + "\"instrument_data\":{"
+                + "  \"account_number\":\"FR7630006000011234567890189\","
+                + "  \"country\":\"FR\","
+                + "  \"currency\":\"EUR\""
+                + "},"
+                + "\"account_holder\":{"
+                + "  \"first_name\":\"Jean\","
+                + "  \"last_name\":\"Martin\""
+                + "}"
+                + "}";
+
+        final CreateInstrumentSepaRequest request = serializer.fromJson(json, CreateInstrumentSepaRequest.class);
+
+        assertNotNull(request);
+        assertNotNull(request.getInstrumentData());
+        assertEquals("FR7630006000011234567890189", request.getInstrumentData().getAccoountNumber());
+        assertEquals(CountryCode.FR, request.getInstrumentData().getCountry());
+        assertEquals(Currency.EUR, request.getInstrumentData().getCurrency());
+        assertNotNull(request.getAccountHolder());
+        assertEquals("Jean", request.getAccountHolder().getFirstName());
+        assertEquals("Martin", request.getAccountHolder().getLastName());
+    }
+
+    @Test
+    void shouldRoundTripSerialize() {
+        final CreateInstrumentSepaRequest original = CreateInstrumentSepaRequest.builder()
+                .instrumentData(InstrumentData.builder()
+                        .accoountNumber("ES9121000418450200051332")
+                        .country(CountryCode.ES)
+                        .currency(Currency.EUR)
+                        .paymentType(PaymentType.RECURRING)
+                        .build())
+                .accountHolder(AccountHolder.builder()
+                        .firstName("Carlos")
+                        .lastName("García")
+                        .billingAddress(Address.builder()
+                                .addressLine1("Calle Mayor 1")
+                                .city("Madrid")
+                                .country(CountryCode.ES)
+                                .build())
+                        .build())
+                .build();
+
+        final String json = serializer.toJson(original);
+        final CreateInstrumentSepaRequest deserialized = serializer.fromJson(json, CreateInstrumentSepaRequest.class);
+
+        assertNotNull(deserialized);
+        assertNotNull(deserialized.getInstrumentData());
+        assertEquals("ES9121000418450200051332", deserialized.getInstrumentData().getAccoountNumber());
+        assertEquals(CountryCode.ES, deserialized.getInstrumentData().getCountry());
+        assertNotNull(deserialized.getAccountHolder());
+        assertEquals("Carlos", deserialized.getAccountHolder().getFirstName());
+        assertEquals("García", deserialized.getAccountHolder().getLastName());
+    }
+
+    @Test
+    void shouldNotSerializeNullOptionalCustomer() {
+        final CreateInstrumentSepaRequest request = CreateInstrumentSepaRequest.builder()
+                .instrumentData(InstrumentData.builder().build())
+                .accountHolder(AccountHolder.builder().build())
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertFalse(json.contains("\"customer\""));
+    }
+
+    @Test
+    void shouldHandleAbsentOptionalCustomer() {
+        final String json = "{"
+                + "\"type\":\"sepa\","
+                + "\"instrument_data\":{},"
+                + "\"account_holder\":{}"
+                + "}";
+
+        final CreateInstrumentSepaRequest request = serializer.fromJson(json, CreateInstrumentSepaRequest.class);
+
+        assertNotNull(request);
+        assertDoesNotThrow(() -> serializer.toJson(request));
+        assertNull(request.getCustomer());
+    }
+}
diff --git a/src/test/java/com/checkout/instruments/get/GetCardInstrumentResponseSerializationTest.java b/src/test/java/com/checkout/instruments/get/GetCardInstrumentResponseSerializationTest.java
new file mode 100644
index 00000000..06264525
--- /dev/null
+++ b/src/test/java/com/checkout/instruments/get/GetCardInstrumentResponseSerializationTest.java
@@ -0,0 +1,187 @@
+package com.checkout.instruments.get;
+
+import com.checkout.GsonSerializer;
+import com.checkout.common.CardCategory;
+import com.checkout.common.CardType;
+import com.checkout.common.CardWalletType;
+import com.checkout.common.CountryCode;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class GetCardInstrumentResponseSerializationTest {
+
+    private final GsonSerializer serializer = new GsonSerializer();
+
+    @Test
+    void shouldDeserializeMinimalResponse() {
+        final String json = "{"
+                + "\"type\":\"card\","
+                + "\"id\":\"src_wmlfc3zyhqzehihu7giusaaawu\","
+                + "\"expiry_month\":6,"
+                + "\"expiry_year\":2025,"
+                + "\"last4\":\"1234\","
+                + "\"regulated_indicator\":true"
+                + "}";
+
+        final GetCardInstrumentResponse response = serializer.fromJson(json, GetCardInstrumentResponse.class);
+
+        assertNotNull(response);
+        assertEquals(6, response.getExpiryMonth());
+        assertEquals(2025, response.getExpiryYear());
+        assertEquals("1234", response.getLast4());
+        assertTrue(response.getRegulatedIndicator());
+    }
+
+    @Test
+    void shouldDeserializeEncryptedCardNumber() {
+        final String json = "{"
+                + "\"type\":\"card\","
+                + "\"id\":\"src_wmlfc3zyhqzehihu7giusaaawu\","
+                + "\"last4\":\"4242\","
+                + "\"regulated_indicator\":false,"
+                + "\"encrypted_card_number\":\"eyJhbGciOiJSU0EtT0FFUC0yNTYifQ...\""
+                + "}";
+
+        final GetCardInstrumentResponse response = serializer.fromJson(json, GetCardInstrumentResponse.class);
+
+        assertNotNull(response);
+        assertEquals("eyJhbGciOiJSU0EtT0FFUC0yNTYifQ...", response.getEncryptedCardNumber());
+    }
+
+    @Test
+    void shouldDeserializeNetworkToken() {
+        final String json = "{"
+                + "\"type\":\"card\","
+                + "\"id\":\"src_wmlfc3zyhqzehihu7giusaaawu\","
+                + "\"last4\":\"4242\","
+                + "\"regulated_indicator\":false,"
+                + "\"network_token\":{"
+                + "  \"id\":\"nt_abcdefghijklmnopqrstuvwxyz12\","
+                + "  \"state\":\"active\""
+                + "}"
+                + "}";
+
+        final GetCardInstrumentResponse response = serializer.fromJson(json, GetCardInstrumentResponse.class);
+
+        assertNotNull(response);
+        assertNotNull(response.getNetworkToken());
+        assertEquals("nt_abcdefghijklmnopqrstuvwxyz12", response.getNetworkToken().getId());
+        assertEquals(NetworkTokenState.ACTIVE, response.getNetworkToken().getState());
+    }
+
+    @Test
+    void shouldDeserializeNetworkTokenStates() {
+        for (final String state : new String[]{"active", "suspended", "inactive"}) {
+            final String json = "{\"type\":\"card\",\"last4\":\"4242\",\"regulated_indicator\":false,"
+                    + "\"network_token\":{\"id\":\"nt_abcdefghijklmnopqrstuvwxyz12\",\"state\":\"" + state + "\"}}";
+            final GetCardInstrumentResponse response = serializer.fromJson(json, GetCardInstrumentResponse.class);
+            assertNotNull(response.getNetworkToken().getState(), "State should not be null for: " + state);
+        }
+    }
+
+    @Test
+    void shouldDeserializeCardWalletType() {
+        final String jsonGpay = "{"
+                + "\"type\":\"card\",\"last4\":\"4242\",\"regulated_indicator\":false,"
+                + "\"card_wallet_type\":\"googlepay\""
+                + "}";
+        final String jsonApay = "{"
+                + "\"type\":\"card\",\"last4\":\"4242\",\"regulated_indicator\":false,"
+                + "\"card_wallet_type\":\"applepay\""
+                + "}";
+
+        final GetCardInstrumentResponse gpay = serializer.fromJson(jsonGpay, GetCardInstrumentResponse.class);
+        final GetCardInstrumentResponse apay = serializer.fromJson(jsonApay, GetCardInstrumentResponse.class);
+
+        assertEquals(CardWalletType.GOOGLEPAY, gpay.getCardWalletType());
+        assertEquals(CardWalletType.APPLEPAY, apay.getCardWalletType());
+    }
+
+    @Test
+    void shouldDeserializeFullResponse() {
+        final String json = "{"
+                + "\"type\":\"card\","
+                + "\"id\":\"src_wmlfc3zyhqzehihu7giusaaawu\","
+                + "\"fingerprint\":\"vnsdrvikkvre3dtrjpwv7ire7u\","
+                + "\"expiry_month\":6,"
+                + "\"expiry_year\":2025,"
+                + "\"name\":\"John Smith\","
+                + "\"scheme\":\"Visa\","
+                + "\"scheme_local\":\"Cartes Bancaires\","
+                + "\"last4\":\"4242\","
+                + "\"bin\":\"424242\","
+                + "\"card_type\":\"Credit\","
+                + "\"card_category\":\"Consumer\","
+                + "\"issuer\":\"JPMORGAN CHASE BANK NA\","
+                + "\"issuer_country\":\"US\","
+                + "\"product_id\":\"A\","
+                + "\"product_type\":\"Visa Traditional\","
+                + "\"encrypted_card_number\":\"eyJhbGciOiJSU0EtT0FFUC0yNTYifQ...\","
+                + "\"network_token\":{\"id\":\"nt_abcdefghijklmnopqrstuvwxyz12\",\"state\":\"active\"},"
+                + "\"card_wallet_type\":\"googlepay\","
+                + "\"regulated_indicator\":true"
+                + "}";
+
+        final GetCardInstrumentResponse response = serializer.fromJson(json, GetCardInstrumentResponse.class);
+
+        assertNotNull(response);
+        assertEquals("src_wmlfc3zyhqzehihu7giusaaawu", response.getId());
+        assertEquals(6, response.getExpiryMonth());
+        assertEquals("John Smith", response.getName());
+        assertEquals("Visa", response.getScheme());
+        assertEquals("4242", response.getLast4());
+        assertEquals(CardType.CREDIT, response.getCardType());
+        assertEquals(CardCategory.CONSUMER, response.getCardCategory());
+        assertEquals(CountryCode.US, response.getIssuerCountry());
+        assertEquals("eyJhbGciOiJSU0EtT0FFUC0yNTYifQ...", response.getEncryptedCardNumber());
+        assertNotNull(response.getNetworkToken());
+        assertEquals(NetworkTokenState.ACTIVE, response.getNetworkToken().getState());
+        assertEquals(CardWalletType.GOOGLEPAY, response.getCardWalletType());
+        assertTrue(response.getRegulatedIndicator());
+    }
+
+    @Test
+    void shouldRoundTripSerialize() {
+        final String original = "{"
+                + "\"type\":\"card\","
+                + "\"id\":\"src_wmlfc3zyhqzehihu7giusaaawu\","
+                + "\"last4\":\"4242\","
+                + "\"encrypted_card_number\":\"eyJhbGciOiJSU0EtT0FFUC0yNTYifQ...\","
+                + "\"network_token\":{\"id\":\"nt_abcdefghijklmnopqrstuvwxyz12\",\"state\":\"suspended\"},"
+                + "\"card_wallet_type\":\"applepay\","
+                + "\"regulated_indicator\":true"
+                + "}";
+
+        final GetCardInstrumentResponse response = serializer.fromJson(original, GetCardInstrumentResponse.class);
+        final String reserialised = serializer.toJson(response);
+        final GetCardInstrumentResponse roundTripped = serializer.fromJson(reserialised, GetCardInstrumentResponse.class);
+
+        assertNotNull(roundTripped);
+        assertEquals(response.getId(), roundTripped.getId());
+        assertEquals(response.getEncryptedCardNumber(), roundTripped.getEncryptedCardNumber());
+        assertEquals(response.getNetworkToken().getState(), roundTripped.getNetworkToken().getState());
+        assertEquals(response.getCardWalletType(), roundTripped.getCardWalletType());
+        assertEquals(response.getRegulatedIndicator(), roundTripped.getRegulatedIndicator());
+    }
+
+    @Test
+    void shouldHandleAbsentOptionalFields() {
+        final String json = "{"
+                + "\"type\":\"card\","
+                + "\"last4\":\"4242\","
+                + "\"regulated_indicator\":false"
+                + "}";
+
+        final GetCardInstrumentResponse response = serializer.fromJson(json, GetCardInstrumentResponse.class);
+
+        assertNotNull(response);
+        assertDoesNotThrow(() -> serializer.toJson(response));
+        assertEquals(null, response.getEncryptedCardNumber());
+        assertEquals(null, response.getNetworkToken());
+        assertEquals(null, response.getCardWalletType());
+    }
+}
diff --git a/src/test/java/com/checkout/payments/AccommodationDataSerializationTest.java b/src/test/java/com/checkout/payments/AccommodationDataSerializationTest.java
new file mode 100644
index 00000000..e600277d
--- /dev/null
+++ b/src/test/java/com/checkout/payments/AccommodationDataSerializationTest.java
@@ -0,0 +1,165 @@
+package com.checkout.payments;
+
+import com.checkout.GsonSerializer;
+import com.checkout.common.Address;
+import com.checkout.common.CountryCode;
+import com.checkout.common.Phone;
+import org.junit.jupiter.api.Test;
+
+import java.time.LocalDate;
+import java.util.Arrays;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
+
+class AccommodationDataSerializationTest {
+
+    private final GsonSerializer serializer = new GsonSerializer();
+
+    @Test
+    void shouldSerializeWithRequiredFields() {
+        final AccommodationData data = AccommodationData.builder()
+                .name("Grand Hotel")
+                .checkInDate(LocalDate.of(2025, 6, 1))
+                .checkOutDate(LocalDate.of(2025, 6, 5))
+                .build();
+
+        assertDoesNotThrow(() -> serializer.toJson(data));
+    }
+
+    @Test
+    void shouldSerializeWithAllOptionalFields() {
+        final AccommodationData data = AccommodationData.builder()
+                .name("Grand Hotel")
+                .bookingReference("BK-12345")
+                .checkInDate(LocalDate.of(2025, 6, 1))
+                .checkOutDate(LocalDate.of(2025, 6, 5))
+                .address(Address.builder()
+                        .addressLine1("1 Hotel Plaza")
+                        .city("Paris")
+                        .country(CountryCode.FR)
+                        .build())
+                .country(CountryCode.FR)
+                .city("Paris")
+                .numberOfRooms(2)
+                .guests(Arrays.asList(
+                        AccommodationGuest.builder()
+                                .firstName("John")
+                                .lastName("Smith")
+                                .dateOfBirth(LocalDate.of(1985, 3, 15))
+                                .build()
+                ))
+                .room(Arrays.asList(
+                        AccommodationRoom.builder()
+                                .rate("150.00")
+                                .numberOfNightsAtRoomRate("4")
+                                .build()
+                ))
+                .propertyPhone(Arrays.asList(
+                        Phone.builder().countryCode("+33").number("123456789").build()
+                ))
+                .customerServicePhone(Arrays.asList(
+                        Phone.builder().countryCode("+33").number("987654321").build()
+                ))
+                .build();
+
+        assertDoesNotThrow(() -> serializer.toJson(data));
+    }
+
+    @Test
+    void shouldSerializeDatesAsLocalDate() {
+        final AccommodationData data = AccommodationData.builder()
+                .checkInDate(LocalDate.of(2025, 6, 1))
+                .checkOutDate(LocalDate.of(2025, 6, 5))
+                .build();
+
+        final String json = serializer.toJson(data);
+
+        assertNotNull(json);
+    }
+
+    @Test
+    void shouldDeserializeFromJson() {
+        final String json = "{"
+                + "\"name\":\"Grand Hotel\","
+                + "\"booking_reference\":\"BK-12345\","
+                + "\"check_in_date\":\"2025-06-01\","
+                + "\"check_out_date\":\"2025-06-05\","
+                + "\"country\":\"FR\","
+                + "\"city\":\"Paris\","
+                + "\"number_of_rooms\":2,"
+                + "\"guests\":[{"
+                + "  \"first_name\":\"John\","
+                + "  \"last_name\":\"Smith\","
+                + "  \"date_of_birth\":\"1985-03-15\""
+                + "}],"
+                + "\"room\":[{"
+                + "  \"rate\":\"150.00\","
+                + "  \"number_of_nights_at_room_rate\":\"4\""
+                + "}]"
+                + "}";
+
+        final AccommodationData data = serializer.fromJson(json, AccommodationData.class);
+
+        assertNotNull(data);
+        assertEquals("Grand Hotel", data.getName());
+        assertEquals("BK-12345", data.getBookingReference());
+        assertEquals(LocalDate.of(2025, 6, 1), data.getCheckInDate());
+        assertEquals(LocalDate.of(2025, 6, 5), data.getCheckOutDate());
+        assertEquals(CountryCode.FR, data.getCountry());
+        assertEquals("Paris", data.getCity());
+        assertEquals(2, data.getNumberOfRooms());
+        assertNotNull(data.getGuests());
+        assertEquals(1, data.getGuests().size());
+        assertEquals("John", data.getGuests().get(0).getFirstName());
+        assertEquals(LocalDate.of(1985, 3, 15), data.getGuests().get(0).getDateOfBirth());
+        assertNotNull(data.getRoom());
+        assertEquals("150.00", data.getRoom().get(0).getRate());
+    }
+
+    @Test
+    void shouldRoundTripSerialize() {
+        final AccommodationData original = AccommodationData.builder()
+                .name("Grand Hotel")
+                .bookingReference("BK-12345")
+                .checkInDate(LocalDate.of(2025, 6, 1))
+                .checkOutDate(LocalDate.of(2025, 6, 5))
+                .country(CountryCode.FR)
+                .numberOfRooms(1)
+                .guests(Arrays.asList(
+                        AccommodationGuest.builder()
+                                .firstName("John")
+                                .lastName("Smith")
+                                .build()
+                ))
+                .build();
+
+        final String json = serializer.toJson(original);
+        final AccommodationData deserialized = serializer.fromJson(json, AccommodationData.class);
+
+        assertNotNull(deserialized);
+        assertEquals("Grand Hotel", deserialized.getName());
+        assertEquals("BK-12345", deserialized.getBookingReference());
+        assertEquals(LocalDate.of(2025, 6, 1), deserialized.getCheckInDate());
+        assertEquals(CountryCode.FR, deserialized.getCountry());
+        assertEquals(1, deserialized.getNumberOfRooms());
+        assertNotNull(deserialized.getGuests());
+        assertEquals("John", deserialized.getGuests().get(0).getFirstName());
+    }
+
+    @Test
+    void shouldHandleAbsentOptionalFields() {
+        final String json = "{}";
+
+        final AccommodationData data = serializer.fromJson(json, AccommodationData.class);
+
+        assertNotNull(data);
+        assertDoesNotThrow(() -> serializer.toJson(data));
+        assertNull(data.getName());
+        assertNull(data.getCheckInDate());
+        assertNull(data.getGuests());
+        assertNull(data.getRoom());
+    }
+}
diff --git a/src/test/java/com/checkout/payments/PaymentProcessingSerializationTest.java b/src/test/java/com/checkout/payments/PaymentProcessingSerializationTest.java
new file mode 100644
index 00000000..16574973
--- /dev/null
+++ b/src/test/java/com/checkout/payments/PaymentProcessingSerializationTest.java
@@ -0,0 +1,228 @@
+package com.checkout.payments;
+
+import com.checkout.GsonSerializer;
+import com.checkout.common.CountryCode;
+import org.junit.jupiter.api.Test;
+
+import java.util.Arrays;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
+
+class PaymentProcessingSerializationTest {
+
+    private final GsonSerializer serializer = new GsonSerializer();
+
+    @Test
+    void shouldDeserializeRetrievalReferenceNumber() {
+        final String json = "{\"retrieval_reference_number\":\"RRN123456\"}";
+
+        final PaymentProcessing processing = serializer.fromJson(json, PaymentProcessing.class);
+
+        assertNotNull(processing);
+        assertEquals("RRN123456", processing.getRetrievalReferenceNumber());
+    }
+
+    @Test
+    void shouldDeserializeAcquirerFields() {
+        final String json = "{"
+                + "\"acquirer_transaction_id\":\"TXN001\","
+                + "\"acquirer_name\":\"Test Acquirer\","
+                + "\"acquirer_country_code\":\"US\""
+                + "}";
+
+        final PaymentProcessing processing = serializer.fromJson(json, PaymentProcessing.class);
+
+        assertNotNull(processing);
+        assertEquals("TXN001", processing.getAcquirerTransactionId());
+        assertEquals("Test Acquirer", processing.getAcquirerName());
+        assertEquals(CountryCode.US, processing.getAcquirerCountryCode());
+    }
+
+    @Test
+    void shouldDeserializePanTypeProcessedFpan() {
+        final String json = "{\"pan_type_processed\":\"fpan\"}";
+
+        final PaymentProcessing processing = serializer.fromJson(json, PaymentProcessing.class);
+
+        assertNotNull(processing);
+        assertEquals(PanProcessedType.FPAN, processing.getPanTypeProcessed());
+    }
+
+    @Test
+    void shouldDeserializePanTypeProcessedDpan() {
+        final String json = "{\"pan_type_processed\":\"dpan\"}";
+
+        final PaymentProcessing processing = serializer.fromJson(json, PaymentProcessing.class);
+
+        assertNotNull(processing);
+        assertEquals(PanProcessedType.DPAN, processing.getPanTypeProcessed());
+    }
+
+    @Test
+    void shouldDeserializeCkoNetworkTokenAvailable() {
+        final String json = "{\"cko_network_token_available\":true}";
+
+        final PaymentProcessing processing = serializer.fromJson(json, PaymentProcessing.class);
+
+        assertNotNull(processing);
+        assertEquals(Boolean.TRUE, processing.getCkoNetworkTokenAvailable());
+    }
+
+    @Test
+    void shouldDeserializeBizumPaymentId() {
+        final String json = "{\"bizum_payment_id\":\"bizum_abc123\"}";
+
+        final PaymentProcessing processing = serializer.fromJson(json, PaymentProcessing.class);
+
+        assertNotNull(processing);
+        assertEquals("bizum_abc123", processing.getBizumPaymentId());
+    }
+
+    @Test
+    void shouldDeserializeReconciliationId() {
+        final String json = "{\"reconciliation_id\":\"recon_001\"}";
+
+        final PaymentProcessing processing = serializer.fromJson(json, PaymentProcessing.class);
+
+        assertNotNull(processing);
+        assertEquals("recon_001", processing.getReconciliationId());
+    }
+
+    @Test
+    void shouldDeserializePartnerFields() {
+        final String json = "{"
+                + "\"partner_order_id\":\"po_001\","
+                + "\"partner_session_id\":\"ps_001\","
+                + "\"partner_client_token\":\"pct_001\","
+                + "\"partner_payment_id\":\"pp_001\","
+                + "\"partner_status\":\"APPROVED\","
+                + "\"partner_transaction_id\":\"pt_001\","
+                + "\"partner_merchant_advice_code\":\"01\","
+                + "\"partner_response_code\":\"00\","
+                + "\"partner_authorization_code\":\"auth_001\","
+                + "\"partner_authorization_response_code\":\"resp_001\","
+                + "\"partner_error_codes\":[\"ERR001\",\"ERR002\"],"
+                + "\"partner_error_message\":\"Declined\""
+                + "}";
+
+        final PaymentProcessing processing = serializer.fromJson(json, PaymentProcessing.class);
+
+        assertNotNull(processing);
+        assertEquals("po_001", processing.getPartnerOrderId());
+        assertEquals("ps_001", processing.getPartnerSessionId());
+        assertEquals("pct_001", processing.getPartnerClientToken());
+        assertEquals("pp_001", processing.getPartnerPaymentId());
+        assertEquals("APPROVED", processing.getPartnerStatus());
+        assertEquals("pt_001", processing.getPartnerTransactionId());
+        assertEquals("01", processing.getPartnerMerchantAdviceCode());
+        assertEquals("00", processing.getPartnerResponseCode());
+        assertEquals("auth_001", processing.getPartnerAuthorizationCode());
+        assertEquals("resp_001", processing.getPartnerAuthorizationResponseCode());
+        assertEquals(Arrays.asList("ERR001", "ERR002"), processing.getPartnerErrorCodes());
+        assertEquals("Declined", processing.getPartnerErrorMessage());
+    }
+
+    @Test
+    void shouldDeserializeSchemeMerchantId() {
+        final String json = "{"
+                + "\"scheme_merchant_id\":\"sm_001\","
+                + "\"recommendation_code\":\"RC001\","
+                + "\"merchant_category_code\":\"5411\","
+                + "\"scheme\":\"Visa\","
+                + "\"pun\":\"PUN123456\""
+                + "}";
+
+        final PaymentProcessing processing = serializer.fromJson(json, PaymentProcessing.class);
+
+        assertNotNull(processing);
+        assertEquals("sm_001", processing.getSchemeMerchantId());
+        assertEquals("RC001", processing.getRecommendationCode());
+        assertEquals("5411", processing.getMerchantCategoryCode());
+        assertEquals("Visa", processing.getScheme());
+        assertEquals("PUN123456", processing.getPun());
+    }
+
+    @Test
+    void shouldDeserializeForeignRetailerAmount() {
+        final String json = "{"
+                + "\"foreign_retailer_amount\":750,"
+                + "\"surcharge_amount\":50,"
+                + "\"provision_network_token\":true,"
+                + "\"aft\":true"
+                + "}";
+
+        final PaymentProcessing processing = serializer.fromJson(json, PaymentProcessing.class);
+
+        assertNotNull(processing);
+        assertEquals(750L, processing.getForeignRetailerAmount());
+        assertEquals(50L, processing.getSurchargeAmount());
+        assertEquals(Boolean.TRUE, processing.getProvisionNetworkToken());
+        assertEquals(Boolean.TRUE, processing.getAft());
+    }
+
+    @Test
+    void shouldDeserializeFullSwaggerExample() {
+        final String json = "{"
+                + "\"retrieval_reference_number\":\"RRN001\","
+                + "\"acquirer_transaction_id\":\"ACQ001\","
+                + "\"acquirer_name\":\"Acquirer Bank\","
+                + "\"acquirer_country_code\":\"GB\","
+                + "\"recommendation_code\":\"R001\","
+                + "\"scheme\":\"Mastercard\","
+                + "\"pan_type_processed\":\"fpan\","
+                + "\"cko_network_token_available\":false,"
+                + "\"purchase_country\":\"GB\","
+                + "\"scheme_merchant_id\":\"SMI001\","
+                + "\"foreign_retailer_amount\":100,"
+                + "\"provision_network_token\":false,"
+                + "\"merchant_category_code\":\"5812\","
+                + "\"aft\":false,"
+                + "\"bizum_payment_id\":\"biz_001\","
+                + "\"reconciliation_id\":\"rec_001\""
+                + "}";
+
+        final PaymentProcessing processing = serializer.fromJson(json, PaymentProcessing.class);
+
+        assertNotNull(processing);
+        assertEquals("RRN001", processing.getRetrievalReferenceNumber());
+        assertEquals("ACQ001", processing.getAcquirerTransactionId());
+        assertEquals("Acquirer Bank", processing.getAcquirerName());
+        assertEquals(CountryCode.GB, processing.getAcquirerCountryCode());
+        assertEquals(PanProcessedType.FPAN, processing.getPanTypeProcessed());
+        assertEquals(Boolean.FALSE, processing.getCkoNetworkTokenAvailable());
+        assertEquals(CountryCode.GB, processing.getPurchaseCountry());
+        assertEquals("SMI001", processing.getSchemeMerchantId());
+        assertEquals(100L, processing.getForeignRetailerAmount());
+        assertEquals("biz_001", processing.getBizumPaymentId());
+        assertEquals("rec_001", processing.getReconciliationId());
+    }
+
+    @Test
+    void shouldHandleAbsentOptionalFields() {
+        final String json = "{}";
+
+        final PaymentProcessing processing = serializer.fromJson(json, PaymentProcessing.class);
+
+        assertNotNull(processing);
+        assertDoesNotThrow(() -> serializer.toJson(processing));
+        assertNull(processing.getRetrievalReferenceNumber());
+        assertNull(processing.getPanTypeProcessed());
+        assertNull(processing.getCkoNetworkTokenAvailable());
+        assertNull(processing.getBizumPaymentId());
+    }
+
+    @Test
+    void shouldNotSerializeNullFields() {
+        final PaymentProcessing processing = new PaymentProcessing();
+
+        final String json = serializer.toJson(processing);
+
+        assertFalse(json.contains("\"retrieval_reference_number\""));
+        assertFalse(json.contains("\"pan_type_processed\""));
+        assertFalse(json.contains("\"cko_network_token_available\""));
+    }
+}
diff --git a/src/test/java/com/checkout/payments/ProcessingSettingsSerializationTest.java b/src/test/java/com/checkout/payments/ProcessingSettingsSerializationTest.java
new file mode 100644
index 00000000..c890349b
--- /dev/null
+++ b/src/test/java/com/checkout/payments/ProcessingSettingsSerializationTest.java
@@ -0,0 +1,205 @@
+package com.checkout.payments;
+
+import com.checkout.GsonSerializer;
+import com.checkout.common.CardType;
+import com.checkout.common.CountryCode;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class ProcessingSettingsSerializationTest {
+
+    private final GsonSerializer serializer = new GsonSerializer();
+
+    @Test
+    void shouldSerializePanPreferenceFpan() {
+        final ProcessingSettings settings = ProcessingSettings.builder()
+                .panPreference(PanProcessedType.FPAN)
+                .build();
+
+        final String json = serializer.toJson(settings);
+
+        assertTrue(json.contains("\"pan_preference\":\"fpan\""));
+    }
+
+    @Test
+    void shouldSerializePanPreferenceDpan() {
+        final ProcessingSettings settings = ProcessingSettings.builder()
+                .panPreference(PanProcessedType.DPAN)
+                .build();
+
+        final String json = serializer.toJson(settings);
+
+        assertTrue(json.contains("\"pan_preference\":\"dpan\""));
+    }
+
+    @Test
+    void shouldSerializeServiceTypeSameDay() {
+        final ProcessingSettings settings = ProcessingSettings.builder()
+                .serviceType(AchServiceType.SAME_DAY)
+                .build();
+
+        final String json = serializer.toJson(settings);
+
+        assertTrue(json.contains("\"service_type\":\"same_day\""));
+    }
+
+    @Test
+    void shouldSerializeServiceTypeStandard() {
+        final ProcessingSettings settings = ProcessingSettings.builder()
+                .serviceType(AchServiceType.STANDARD)
+                .build();
+
+        final String json = serializer.toJson(settings);
+
+        assertTrue(json.contains("\"service_type\":\"standard\""));
+    }
+
+    @Test
+    void shouldSerializeAffiliateFields() {
+        final ProcessingSettings settings = ProcessingSettings.builder()
+                .affiliateId("AFFILIATE123")
+                .affiliateUrl("https://affiliate.example.com")
+                .build();
+
+        final String json = serializer.toJson(settings);
+
+        assertTrue(json.contains("\"affiliate_id\":\"AFFILIATE123\""));
+        assertTrue(json.contains("\"affiliate_url\":\"https://affiliate.example.com\""));
+    }
+
+    @Test
+    void shouldSerializeCardTypeCredit() {
+        final ProcessingSettings settings = ProcessingSettings.builder()
+                .cardType(CardType.CREDIT)
+                .build();
+
+        final String json = serializer.toJson(settings);
+
+        assertTrue(json.contains("\"card_type\":\"Credit\""));
+    }
+
+    @Test
+    void shouldSerializeCardTypeDebit() {
+        final ProcessingSettings settings = ProcessingSettings.builder()
+                .cardType(CardType.DEBIT)
+                .build();
+
+        final String json = serializer.toJson(settings);
+
+        assertTrue(json.contains("\"card_type\":\"Debit\""));
+    }
+
+    @Test
+    void shouldSerializeForeignRetailerAmount() {
+        final ProcessingSettings settings = ProcessingSettings.builder()
+                .foreignRetailerAmount(500L)
+                .build();
+
+        final String json = serializer.toJson(settings);
+
+        assertTrue(json.contains("\"foreign_retailer_amount\":500"));
+    }
+
+    @Test
+    void shouldSerializeReconciliationId() {
+        final ProcessingSettings settings = ProcessingSettings.builder()
+                .reconciliationId("recon_abc123")
+                .build();
+
+        final String json = serializer.toJson(settings);
+
+        assertTrue(json.contains("\"reconciliation_id\":\"recon_abc123\""));
+    }
+
+    @Test
+    void shouldDeserializePanPreference() {
+        final String json = "{\"pan_preference\":\"fpan\",\"service_type\":\"standard\"}";
+
+        final ProcessingSettings settings = serializer.fromJson(json, ProcessingSettings.class);
+
+        assertNotNull(settings);
+        assertEquals(PanProcessedType.FPAN, settings.getPanPreference());
+        assertEquals(AchServiceType.STANDARD, settings.getServiceType());
+    }
+
+    @Test
+    void shouldDeserializeAffiliateAndCardType() {
+        final String json = "{"
+                + "\"affiliate_id\":\"AFF001\","
+                + "\"affiliate_url\":\"https://aff.example.com\","
+                + "\"card_type\":\"Debit\","
+                + "\"foreign_retailer_amount\":1000,"
+                + "\"reconciliation_id\":\"rec_001\""
+                + "}";
+
+        final ProcessingSettings settings = serializer.fromJson(json, ProcessingSettings.class);
+
+        assertNotNull(settings);
+        assertEquals("AFF001", settings.getAffiliateId());
+        assertEquals("https://aff.example.com", settings.getAffiliateUrl());
+        assertEquals(CardType.DEBIT, settings.getCardType());
+        assertEquals(1000L, settings.getForeignRetailerAmount());
+        assertEquals("rec_001", settings.getReconciliationId());
+    }
+
+    @Test
+    void shouldRoundTripSerialize() {
+        final ProcessingSettings original = ProcessingSettings.builder()
+                .panPreference(PanProcessedType.DPAN)
+                .serviceType(AchServiceType.SAME_DAY)
+                .affiliateId("AFF123")
+                .affiliateUrl("https://example.com")
+                .cardType(CardType.CREDIT)
+                .foreignRetailerAmount(250L)
+                .reconciliationId("rec_xyz")
+                .hubModelOriginationCountry(CountryCode.GB)
+                .build();
+
+        final String json = serializer.toJson(original);
+        final ProcessingSettings deserialized = serializer.fromJson(json, ProcessingSettings.class);
+
+        assertNotNull(deserialized);
+        assertEquals(PanProcessedType.DPAN, deserialized.getPanPreference());
+        assertEquals(AchServiceType.SAME_DAY, deserialized.getServiceType());
+        assertEquals("AFF123", deserialized.getAffiliateId());
+        assertEquals("https://example.com", deserialized.getAffiliateUrl());
+        assertEquals(CardType.CREDIT, deserialized.getCardType());
+        assertEquals(250L, deserialized.getForeignRetailerAmount());
+        assertEquals("rec_xyz", deserialized.getReconciliationId());
+        assertEquals(CountryCode.GB, deserialized.getHubModelOriginationCountry());
+    }
+
+    @Test
+    void shouldNotSerializeNullOptionalFields() {
+        final ProcessingSettings settings = ProcessingSettings.builder()
+                .orderId("order_001")
+                .build();
+
+        final String json = serializer.toJson(settings);
+
+        assertFalse(json.contains("\"pan_preference\""));
+        assertFalse(json.contains("\"service_type\""));
+        assertFalse(json.contains("\"affiliate_id\""));
+        assertFalse(json.contains("\"card_type\""));
+    }
+
+    @Test
+    void shouldHandleAbsentOptionalFields() {
+        final String json = "{}";
+
+        final ProcessingSettings settings = serializer.fromJson(json, ProcessingSettings.class);
+
+        assertNotNull(settings);
+        assertDoesNotThrow(() -> serializer.toJson(settings));
+        assertNull(settings.getPanPreference());
+        assertNull(settings.getServiceType());
+        assertNull(settings.getAffiliateId());
+        assertNull(settings.getCardType());
+    }
+}
diff --git a/src/test/java/com/checkout/payments/ThreeDSDataSerializationTest.java b/src/test/java/com/checkout/payments/ThreeDSDataSerializationTest.java
new file mode 100644
index 00000000..bff0f7d3
--- /dev/null
+++ b/src/test/java/com/checkout/payments/ThreeDSDataSerializationTest.java
@@ -0,0 +1,149 @@
+package com.checkout.payments;
+
+import com.checkout.GsonSerializer;
+import com.checkout.common.ThreeDSEnrollmentStatus;
+import org.junit.jupiter.api.Test;
+import static com.checkout.payments.TrustedListingStatus.ALLOWLISTED;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class ThreeDSDataSerializationTest {
+
+    private final GsonSerializer serializer = new GsonSerializer();
+
+    @Test
+    void shouldDeserializeMinimalResponse() {
+        final String json = "{\"downgraded\":false}";
+
+        final ThreeDSData data = serializer.fromJson(json, ThreeDSData.class);
+
+        assertNotNull(data);
+        assertEquals(false, data.getDowngraded());
+    }
+
+    @Test
+    void shouldDeserializeEciField() {
+        final String json = "{"
+                + "\"eci\":\"05\","
+                + "\"challenged\":true,"
+                + "\"version\":\"2.1.0\""
+                + "}";
+
+        final ThreeDSData data = serializer.fromJson(json, ThreeDSData.class);
+
+        assertNotNull(data);
+        assertEquals("05", data.getEci());
+        assertTrue(data.getChallenged());
+        assertEquals("2.1.0", data.getVersion());
+    }
+
+    @Test
+    void shouldDeserializeAuthenticationStatusReason() {
+        final String json = "{"
+                + "\"authentication_status_reason\":\"01\","
+                + "\"eci\":\"06\""
+                + "}";
+
+        final ThreeDSData data = serializer.fromJson(json, ThreeDSData.class);
+
+        assertNotNull(data);
+        assertEquals("01", data.getAuthenticationStatusReason());
+        assertEquals("06", data.getEci());
+    }
+
+    @Test
+    void shouldDeserializeTrustedListing() {
+        final String json = "{"
+                + "\"trusted_listing\":{"
+                + "  \"status\":\"Y\","
+                + "  \"source\":\"01\""
+                + "}"
+                + "}";
+
+        final ThreeDSData data = serializer.fromJson(json, ThreeDSData.class);
+
+        assertNotNull(data);
+        assertNotNull(data.getTrustedListing());
+        assertEquals(ALLOWLISTED, data.getTrustedListing().getStatus());
+        assertEquals("01", data.getTrustedListing().getSource());
+    }
+
+    @Test
+    void shouldDeserializeFullResponse() {
+        final String json = "{"
+                + "\"downgraded\":false,"
+                + "\"enrolled\":\"Y\","
+                + "\"upgrade_reason\":\"02\","
+                + "\"signature_valid\":\"Y\","
+                + "\"authentication_response\":\"Y\","
+                + "\"cryptogram\":\"AgAAAAAAAIR8CQrXcIhbQAAAAAA\","
+                + "\"xid\":\"MDAwMDAwMDAwMDAwMDAwMzIyNzY\","
+                + "\"version\":\"2.1.0\","
+                + "\"exemption_applied\":\"low_value\","
+                + "\"challenged\":true,"
+                + "\"eci\":\"05\","
+                + "\"authentication_status_reason\":\"01\","
+                + "\"trusted_listing\":{"
+                + "  \"status\":\"Y\","
+                + "  \"source\":\"01\""
+                + "}"
+                + "}";
+
+        final ThreeDSData data = serializer.fromJson(json, ThreeDSData.class);
+
+        assertNotNull(data);
+        assertEquals(false, data.getDowngraded());
+        assertEquals(ThreeDSEnrollmentStatus.ISSUER_ENROLLED, data.getEnrolled());
+        assertEquals("02", data.getUpgradeReason());
+        assertEquals("Y", data.getSignatureValid());
+        assertEquals("Y", data.getAuthenticationResponse());
+        assertEquals("AgAAAAAAAIR8CQrXcIhbQAAAAAA", data.getCryptogram());
+        assertEquals("MDAwMDAwMDAwMDAwMDAwMzIyNzY", data.getXid());
+        assertEquals("2.1.0", data.getVersion());
+        assertEquals("low_value", data.getExemptionApplied());
+        assertTrue(data.getChallenged());
+        assertEquals("05", data.getEci());
+        assertEquals("01", data.getAuthenticationStatusReason());
+        assertNotNull(data.getTrustedListing());
+        assertEquals(ALLOWLISTED, data.getTrustedListing().getStatus());
+    }
+
+    @Test
+    void shouldRoundTripSerialize() {
+        final String original = "{"
+                + "\"eci\":\"05\","
+                + "\"authentication_status_reason\":\"01\","
+                + "\"trusted_listing\":{\"status\":\"Y\",\"source\":\"01\"},"
+                + "\"challenged\":true,"
+                + "\"version\":\"2.2.0\""
+                + "}";
+
+        final ThreeDSData data = serializer.fromJson(original, ThreeDSData.class);
+        final String reserialised = serializer.toJson(data);
+        final ThreeDSData roundTripped = serializer.fromJson(reserialised, ThreeDSData.class);
+
+        assertNotNull(roundTripped);
+        assertEquals(data.getEci(), roundTripped.getEci());
+        assertEquals(data.getAuthenticationStatusReason(), roundTripped.getAuthenticationStatusReason());
+        assertEquals(data.getTrustedListing().getStatus(), roundTripped.getTrustedListing().getStatus());
+        assertEquals(data.getChallenged(), roundTripped.getChallenged());
+    }
+
+    @Test
+    void shouldHandleAbsentOptionalFields() {
+        final String json = "{}";
+
+        final ThreeDSData data = serializer.fromJson(json, ThreeDSData.class);
+
+        assertNotNull(data);
+        assertDoesNotThrow(() -> serializer.toJson(data));
+        assertNull(data.getEci());
+        assertNull(data.getAuthenticationStatusReason());
+        assertNull(data.getTrustedListing());
+        assertNull(data.getChallenged());
+    }
+}
diff --git a/src/test/java/com/checkout/payments/hosted/HostedPaymentRequestSerializationTest.java b/src/test/java/com/checkout/payments/hosted/HostedPaymentRequestSerializationTest.java
new file mode 100644
index 00000000..5378dca0
--- /dev/null
+++ b/src/test/java/com/checkout/payments/hosted/HostedPaymentRequestSerializationTest.java
@@ -0,0 +1,222 @@
+package com.checkout.payments.hosted;
+
+import com.checkout.GsonSerializer;
+import com.checkout.common.Address;
+import com.checkout.common.CountryCode;
+import com.checkout.common.Currency;
+import com.checkout.payments.BillingInformation;
+import com.checkout.payments.PaymentType;
+import org.junit.jupiter.api.Test;
+
+import java.time.Instant;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class HostedPaymentRequestSerializationTest {
+
+    private final GsonSerializer serializer = new GsonSerializer();
+
+    @Test
+    void shouldSerializeRequiredFields() {
+        final HostedPaymentRequest request = HostedPaymentRequest.builder()
+                .currency(Currency.USD)
+                .billing(BillingInformation.builder()
+                        .address(Address.builder()
+                                .addressLine1("123 Main St")
+                                .city("New York")
+                                .country(CountryCode.US)
+                                .build())
+                        .build())
+                .successUrl("https://example.com/success")
+                .cancelUrl("https://example.com/cancel")
+                .failureUrl("https://example.com/failure")
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertNotNull(json);
+        assertTrue(json.contains("\"currency\":\"USD\""));
+        assertTrue(json.contains("\"billing\""));
+        assertTrue(json.contains("\"success_url\":\"https://example.com/success\""));
+        assertTrue(json.contains("\"cancel_url\":\"https://example.com/cancel\""));
+        assertTrue(json.contains("\"failure_url\":\"https://example.com/failure\""));
+    }
+
+    @Test
+    void shouldSerializeAmount() {
+        final HostedPaymentRequest request = HostedPaymentRequest.builder()
+                .currency(Currency.GBP)
+                .amount(1000L)
+                .successUrl("https://example.com/success")
+                .cancelUrl("https://example.com/cancel")
+                .failureUrl("https://example.com/failure")
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertTrue(json.contains("\"amount\":1000"));
+        assertTrue(json.contains("\"currency\":\"GBP\""));
+    }
+
+    @Test
+    void shouldSerializePaymentType() {
+        final HostedPaymentRequest request = HostedPaymentRequest.builder()
+                .currency(Currency.EUR)
+                .paymentType(PaymentType.RECURRING)
+                .successUrl("https://example.com/success")
+                .cancelUrl("https://example.com/cancel")
+                .failureUrl("https://example.com/failure")
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertTrue(json.contains("\"payment_type\":\"Recurring\""));
+    }
+
+    @Test
+    void shouldSerializeProcessingChannelId() {
+        final HostedPaymentRequest request = HostedPaymentRequest.builder()
+                .currency(Currency.USD)
+                .processingChannelId("pc_abcdefghijklmnopqrstuvwxyz")
+                .successUrl("https://example.com/success")
+                .cancelUrl("https://example.com/cancel")
+                .failureUrl("https://example.com/failure")
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertTrue(json.contains("\"processing_channel_id\":\"pc_abcdefghijklmnopqrstuvwxyz\""));
+    }
+
+    @Test
+    void shouldSerializeCaptureFields() {
+        final Instant captureOn = Instant.parse("2026-06-01T12:00:00Z");
+        final HostedPaymentRequest request = HostedPaymentRequest.builder()
+                .currency(Currency.USD)
+                .capture(true)
+                .captureOn(captureOn)
+                .successUrl("https://example.com/success")
+                .cancelUrl("https://example.com/cancel")
+                .failureUrl("https://example.com/failure")
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertTrue(json.contains("\"capture\":true"));
+        assertTrue(json.contains("\"capture_on\""));
+    }
+
+    @Test
+    void shouldSerializeReferenceAndDescription() {
+        final HostedPaymentRequest request = HostedPaymentRequest.builder()
+                .currency(Currency.USD)
+                .reference("ORD-12345")
+                .description("Test payment")
+                .displayName("My Shop")
+                .successUrl("https://example.com/success")
+                .cancelUrl("https://example.com/cancel")
+                .failureUrl("https://example.com/failure")
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertTrue(json.contains("\"reference\":\"ORD-12345\""));
+        assertTrue(json.contains("\"description\":\"Test payment\""));
+        assertTrue(json.contains("\"display_name\":\"My Shop\""));
+    }
+
+    @Test
+    void shouldDeserializeRequiredFields() {
+        final String json = "{"
+                + "\"currency\":\"USD\","
+                + "\"success_url\":\"https://example.com/success\","
+                + "\"cancel_url\":\"https://example.com/cancel\","
+                + "\"failure_url\":\"https://example.com/failure\","
+                + "\"amount\":500"
+                + "}";
+
+        final HostedPaymentRequest request = serializer.fromJson(json, HostedPaymentRequest.class);
+
+        assertNotNull(request);
+        assertEquals(Currency.USD, request.getCurrency());
+        assertEquals("https://example.com/success", request.getSuccessUrl());
+        assertEquals("https://example.com/cancel", request.getCancelUrl());
+        assertEquals("https://example.com/failure", request.getFailureUrl());
+        assertEquals(500L, request.getAmount());
+    }
+
+    @Test
+    void shouldDeserializePaymentType() {
+        final String json = "{\"payment_type\":\"Recurring\",\"currency\":\"GBP\"}";
+
+        final HostedPaymentRequest request = serializer.fromJson(json, HostedPaymentRequest.class);
+
+        assertNotNull(request);
+        assertEquals(PaymentType.RECURRING, request.getPaymentType());
+    }
+
+    @Test
+    void shouldRoundTripSerialize() {
+        final HostedPaymentRequest original = HostedPaymentRequest.builder()
+                .currency(Currency.EUR)
+                .amount(2500L)
+                .paymentType(PaymentType.REGULAR)
+                .reference("REF-001")
+                .description("Round trip test")
+                .processingChannelId("pc_abcdefghijklmnopqrstuvwxyz")
+                .successUrl("https://example.com/success")
+                .cancelUrl("https://example.com/cancel")
+                .failureUrl("https://example.com/failure")
+                .build();
+
+        final String json = serializer.toJson(original);
+        final HostedPaymentRequest deserialized = serializer.fromJson(json, HostedPaymentRequest.class);
+
+        assertNotNull(deserialized);
+        assertEquals(Currency.EUR, deserialized.getCurrency());
+        assertEquals(2500L, deserialized.getAmount());
+        assertEquals("REF-001", deserialized.getReference());
+        assertEquals("Round trip test", deserialized.getDescription());
+        assertEquals("pc_abcdefghijklmnopqrstuvwxyz", deserialized.getProcessingChannelId());
+        assertEquals("https://example.com/success", deserialized.getSuccessUrl());
+        assertEquals("https://example.com/cancel", deserialized.getCancelUrl());
+        assertEquals("https://example.com/failure", deserialized.getFailureUrl());
+    }
+
+    @Test
+    void shouldNotSerializeNullOptionalFields() {
+        final HostedPaymentRequest request = HostedPaymentRequest.builder()
+                .currency(Currency.USD)
+                .successUrl("https://example.com/success")
+                .cancelUrl("https://example.com/cancel")
+                .failureUrl("https://example.com/failure")
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertFalse(json.contains("\"amount\""));
+        assertFalse(json.contains("\"description\""));
+        assertFalse(json.contains("\"processing_channel_id\""));
+        assertFalse(json.contains("\"capture_on\""));
+    }
+
+    @Test
+    void shouldHandleAbsentOptionalFields() {
+        final String json = "{\"currency\":\"USD\"}";
+
+        final HostedPaymentRequest request = serializer.fromJson(json, HostedPaymentRequest.class);
+
+        assertNotNull(request);
+        assertDoesNotThrow(() -> serializer.toJson(request));
+        assertNull(request.getAmount());
+        assertNull(request.getReference());
+        assertNull(request.getSuccessUrl());
+        assertNull(request.getCancelUrl());
+        assertNull(request.getFailureUrl());
+    }
+}
diff --git a/src/test/java/com/checkout/payments/links/PaymentLinkRequestSerializationTest.java b/src/test/java/com/checkout/payments/links/PaymentLinkRequestSerializationTest.java
new file mode 100644
index 00000000..edf89097
--- /dev/null
+++ b/src/test/java/com/checkout/payments/links/PaymentLinkRequestSerializationTest.java
@@ -0,0 +1,216 @@
+package com.checkout.payments.links;
+
+import com.checkout.GsonSerializer;
+import com.checkout.common.Address;
+import com.checkout.common.CountryCode;
+import com.checkout.common.Currency;
+import com.checkout.payments.BillingInformation;
+import com.checkout.payments.PaymentType;
+import org.junit.jupiter.api.Test;
+
+import java.time.Instant;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class PaymentLinkRequestSerializationTest {
+
+    private final GsonSerializer serializer = new GsonSerializer();
+
+    @Test
+    void shouldSerializeRequiredFields() {
+        final PaymentLinkRequest request = PaymentLinkRequest.builder()
+                .amount(1500L)
+                .currency(Currency.GBP)
+                .billing(BillingInformation.builder()
+                        .address(Address.builder()
+                                .addressLine1("1 High Street")
+                                .city("London")
+                                .country(CountryCode.GB)
+                                .build())
+                        .build())
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertNotNull(json);
+        assertTrue(json.contains("\"amount\":1500"));
+        assertTrue(json.contains("\"currency\":\"GBP\""));
+        assertTrue(json.contains("\"billing\""));
+    }
+
+    @Test
+    void shouldSerializeExpiresIn() {
+        final PaymentLinkRequest request = PaymentLinkRequest.builder()
+                .amount(1000L)
+                .currency(Currency.USD)
+                .expiresIn(86400)
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertTrue(json.contains("\"expires_in\":86400"));
+    }
+
+    @Test
+    void shouldSerializeReturnUrl() {
+        final PaymentLinkRequest request = PaymentLinkRequest.builder()
+                .amount(1000L)
+                .currency(Currency.USD)
+                .returnUrl("https://example.com/return")
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertTrue(json.contains("\"return_url\":\"https://example.com/return\""));
+    }
+
+    @Test
+    void shouldSerializeProcessingChannelId() {
+        final PaymentLinkRequest request = PaymentLinkRequest.builder()
+                .amount(1000L)
+                .currency(Currency.EUR)
+                .processingChannelId("pc_abcdefghijklmnopqrstuvwxyz")
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertTrue(json.contains("\"processing_channel_id\":\"pc_abcdefghijklmnopqrstuvwxyz\""));
+    }
+
+    @Test
+    void shouldSerializePaymentType() {
+        final PaymentLinkRequest request = PaymentLinkRequest.builder()
+                .amount(500L)
+                .currency(Currency.USD)
+                .paymentType(PaymentType.RECURRING)
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertTrue(json.contains("\"payment_type\":\"Recurring\""));
+    }
+
+    @Test
+    void shouldSerializeCaptureFields() {
+        final Instant captureOn = Instant.parse("2026-07-01T10:00:00Z");
+        final PaymentLinkRequest request = PaymentLinkRequest.builder()
+                .amount(1000L)
+                .currency(Currency.USD)
+                .capture(true)
+                .captureOn(captureOn)
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertTrue(json.contains("\"capture\":true"));
+        assertTrue(json.contains("\"capture_on\""));
+    }
+
+    @Test
+    void shouldSerializeReferenceAndDescription() {
+        final PaymentLinkRequest request = PaymentLinkRequest.builder()
+                .amount(750L)
+                .currency(Currency.USD)
+                .reference("ORD-2024-001")
+                .description("Order payment")
+                .displayName("My Store")
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertTrue(json.contains("\"reference\":\"ORD-2024-001\""));
+        assertTrue(json.contains("\"description\":\"Order payment\""));
+        assertTrue(json.contains("\"display_name\":\"My Store\""));
+    }
+
+    @Test
+    void shouldDeserializeRequiredFields() {
+        final String json = "{"
+                + "\"amount\":2000,"
+                + "\"currency\":\"EUR\","
+                + "\"expires_in\":3600,"
+                + "\"return_url\":\"https://example.com/return\","
+                + "\"processing_channel_id\":\"pc_test\""
+                + "}";
+
+        final PaymentLinkRequest request = serializer.fromJson(json, PaymentLinkRequest.class);
+
+        assertNotNull(request);
+        assertEquals(2000L, request.getAmount());
+        assertEquals(Currency.EUR, request.getCurrency());
+        assertEquals(3600, request.getExpiresIn());
+        assertEquals("https://example.com/return", request.getReturnUrl());
+        assertEquals("pc_test", request.getProcessingChannelId());
+    }
+
+    @Test
+    void shouldDeserializePaymentType() {
+        final String json = "{\"payment_type\":\"Installment\",\"amount\":500,\"currency\":\"USD\"}";
+
+        final PaymentLinkRequest request = serializer.fromJson(json, PaymentLinkRequest.class);
+
+        assertNotNull(request);
+        assertEquals(PaymentType.INSTALLMENT, request.getPaymentType());
+    }
+
+    @Test
+    void shouldRoundTripSerialize() {
+        final PaymentLinkRequest original = PaymentLinkRequest.builder()
+                .amount(3000L)
+                .currency(Currency.GBP)
+                .expiresIn(7200)
+                .returnUrl("https://example.com/return")
+                .processingChannelId("pc_abcdefghijklmnopqrstuvwxyz")
+                .reference("REF-RT-001")
+                .description("Round-trip test")
+                .paymentType(PaymentType.REGULAR)
+                .capture(true)
+                .build();
+
+        final String json = serializer.toJson(original);
+        final PaymentLinkRequest deserialized = serializer.fromJson(json, PaymentLinkRequest.class);
+
+        assertNotNull(deserialized);
+        assertEquals(3000L, deserialized.getAmount());
+        assertEquals(Currency.GBP, deserialized.getCurrency());
+        assertEquals(7200, deserialized.getExpiresIn());
+        assertEquals("https://example.com/return", deserialized.getReturnUrl());
+        assertEquals("pc_abcdefghijklmnopqrstuvwxyz", deserialized.getProcessingChannelId());
+        assertEquals("REF-RT-001", deserialized.getReference());
+        assertEquals("Round-trip test", deserialized.getDescription());
+        assertTrue(deserialized.isCapture());
+    }
+
+    @Test
+    void shouldNotSerializeNullOptionalFields() {
+        final PaymentLinkRequest request = PaymentLinkRequest.builder()
+                .amount(1000L)
+                .currency(Currency.USD)
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertFalse(json.contains("\"expires_in\""));
+        assertFalse(json.contains("\"return_url\""));
+        assertFalse(json.contains("\"description\""));
+        assertFalse(json.contains("\"processing_channel_id\""));
+    }
+
+    @Test
+    void shouldHandleAbsentOptionalFields() {
+        final String json = "{\"amount\":500,\"currency\":\"USD\"}";
+
+        final PaymentLinkRequest request = serializer.fromJson(json, PaymentLinkRequest.class);
+
+        assertNotNull(request);
+        assertDoesNotThrow(() -> serializer.toJson(request));
+        assertNull(request.getExpiresIn());
+        assertNull(request.getReturnUrl());
+        assertNull(request.getDescription());
+    }
+}
diff --git a/src/test/java/com/checkout/payments/request/PaymentRequestSerializationTest.java b/src/test/java/com/checkout/payments/request/PaymentRequestSerializationTest.java
new file mode 100644
index 00000000..3e84216d
--- /dev/null
+++ b/src/test/java/com/checkout/payments/request/PaymentRequestSerializationTest.java
@@ -0,0 +1,256 @@
+package com.checkout.payments.request;
+
+import com.checkout.GsonSerializer;
+import com.checkout.common.Currency;
+import com.checkout.payments.AuthorizationType;
+import com.checkout.payments.PaymentType;
+import org.junit.jupiter.api.Test;
+
+import java.time.Instant;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class PaymentRequestSerializationTest {
+
+    private final GsonSerializer serializer = new GsonSerializer();
+
+    @Test
+    void shouldSerializeRequiredCurrencyField() {
+        final PaymentRequest request = PaymentRequest.builder()
+                .currency(Currency.USD)
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertNotNull(json);
+        assertTrue(json.contains("\"currency\":\"USD\""));
+    }
+
+    @Test
+    void shouldSerializePaymentContextId() {
+        final PaymentRequest request = PaymentRequest.builder()
+                .currency(Currency.USD)
+                .paymentContextId("ctx_abc123")
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertTrue(json.contains("\"payment_context_id\":\"ctx_abc123\""));
+    }
+
+    @Test
+    void shouldSerializeMerchantInitiated() {
+        final PaymentRequest request = PaymentRequest.builder()
+                .currency(Currency.USD)
+                .merchantInitiated(true)
+                .paymentType(PaymentType.RECURRING)
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertTrue(json.contains("\"merchant_initiated\":true"));
+        assertTrue(json.contains("\"payment_type\":\"Recurring\""));
+    }
+
+    @Test
+    void shouldSerializePaymentTypeEnum() {
+        for (final PaymentType paymentType : PaymentType.values()) {
+            final PaymentRequest request = PaymentRequest.builder()
+                    .currency(Currency.USD)
+                    .paymentType(paymentType)
+                    .build();
+
+            assertDoesNotThrow(() -> serializer.toJson(request));
+        }
+    }
+
+    @Test
+    void shouldSerializeAuthorizationType() {
+        final PaymentRequest request = PaymentRequest.builder()
+                .currency(Currency.USD)
+                .authorizationType(AuthorizationType.ESTIMATED)
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertTrue(json.contains("\"authorization_type\":\"Estimated\""));
+    }
+
+    @Test
+    void shouldSerializeCaptureFields() {
+        final Instant captureOn = Instant.parse("2026-08-01T14:00:00Z");
+        final PaymentRequest request = PaymentRequest.builder()
+                .currency(Currency.USD)
+                .capture(true)
+                .captureOn(captureOn)
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertTrue(json.contains("\"capture\":true"));
+        assertTrue(json.contains("\"capture_on\""));
+    }
+
+    @Test
+    void shouldSerializeProcessingChannelId() {
+        final PaymentRequest request = PaymentRequest.builder()
+                .currency(Currency.GBP)
+                .processingChannelId("pc_abcdefghijklmnopqrstuvwxyz")
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertTrue(json.contains("\"processing_channel_id\":\"pc_abcdefghijklmnopqrstuvwxyz\""));
+    }
+
+    @Test
+    void shouldSerializePreviousPaymentId() {
+        final PaymentRequest request = PaymentRequest.builder()
+                .currency(Currency.USD)
+                .previousPaymentId("pay_cr4hxwizzp6k7biycuk2ibltnm")
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertTrue(json.contains("\"previous_payment_id\":\"pay_cr4hxwizzp6k7biycuk2ibltnm\""));
+    }
+
+    @Test
+    void shouldSerializeSuccessAndFailureUrls() {
+        final PaymentRequest request = PaymentRequest.builder()
+                .currency(Currency.USD)
+                .successUrl("https://example.com/success")
+                .failureUrl("https://example.com/failure")
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertTrue(json.contains("\"success_url\":\"https://example.com/success\""));
+        assertTrue(json.contains("\"failure_url\":\"https://example.com/failure\""));
+    }
+
+    @Test
+    void shouldSerializeReferenceAndDescription() {
+        final PaymentRequest request = PaymentRequest.builder()
+                .currency(Currency.EUR)
+                .reference("ORD-001")
+                .description("Test order")
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertTrue(json.contains("\"reference\":\"ORD-001\""));
+        assertTrue(json.contains("\"description\":\"Test order\""));
+    }
+
+    @Test
+    void shouldSerializeAmount() {
+        final PaymentRequest request = PaymentRequest.builder()
+                .amount(4999L)
+                .currency(Currency.USD)
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertTrue(json.contains("\"amount\":4999"));
+    }
+
+    @Test
+    void shouldDeserializeKeyFields() {
+        final String json = "{"
+                + "\"payment_context_id\":\"ctx_001\","
+                + "\"amount\":1500,"
+                + "\"currency\":\"GBP\","
+                + "\"payment_type\":\"Unscheduled\","
+                + "\"merchant_initiated\":true,"
+                + "\"reference\":\"REF-001\","
+                + "\"description\":\"Test\","
+                + "\"processing_channel_id\":\"pc_test\","
+                + "\"previous_payment_id\":\"pay_abc\","
+                + "\"success_url\":\"https://example.com/success\","
+                + "\"failure_url\":\"https://example.com/failure\","
+                + "\"capture\":false"
+                + "}";
+
+        final PaymentRequest request = serializer.fromJson(json, PaymentRequest.class);
+
+        assertNotNull(request);
+        assertEquals("ctx_001", request.getPaymentContextId());
+        assertEquals(1500L, request.getAmount());
+        assertEquals(Currency.GBP, request.getCurrency());
+        assertEquals(PaymentType.UNSCHEDULED, request.getPaymentType());
+        assertEquals(Boolean.TRUE, request.getMerchantInitiated());
+        assertEquals("REF-001", request.getReference());
+        assertEquals("Test", request.getDescription());
+        assertEquals("pc_test", request.getProcessingChannelId());
+        assertEquals("pay_abc", request.getPreviousPaymentId());
+        assertEquals("https://example.com/success", request.getSuccessUrl());
+        assertEquals("https://example.com/failure", request.getFailureUrl());
+        assertEquals(Boolean.FALSE, request.getCapture());
+    }
+
+    @Test
+    void shouldRoundTripSerialize() {
+        final PaymentRequest original = PaymentRequest.builder()
+                .amount(2000L)
+                .currency(Currency.USD)
+                .paymentType(PaymentType.MOTO)
+                .reference("RT-001")
+                .description("Round-trip")
+                .processingChannelId("pc_abcdefghijklmnopqrstuvwxyz")
+                .previousPaymentId("pay_prev")
+                .successUrl("https://example.com/success")
+                .failureUrl("https://example.com/failure")
+                .capture(true)
+                .merchantInitiated(false)
+                .build();
+
+        final String json = serializer.toJson(original);
+        final PaymentRequest deserialized = serializer.fromJson(json, PaymentRequest.class);
+
+        assertNotNull(deserialized);
+        assertEquals(2000L, deserialized.getAmount());
+        assertEquals(Currency.USD, deserialized.getCurrency());
+        assertEquals(PaymentType.MOTO, deserialized.getPaymentType());
+        assertEquals("RT-001", deserialized.getReference());
+        assertEquals("pc_abcdefghijklmnopqrstuvwxyz", deserialized.getProcessingChannelId());
+        assertEquals("pay_prev", deserialized.getPreviousPaymentId());
+        assertEquals("https://example.com/success", deserialized.getSuccessUrl());
+        assertEquals("https://example.com/failure", deserialized.getFailureUrl());
+        assertEquals(Boolean.TRUE, deserialized.getCapture());
+    }
+
+    @Test
+    void shouldNotSerializeNullOptionalFields() {
+        final PaymentRequest request = PaymentRequest.builder()
+                .currency(Currency.USD)
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertFalse(json.contains("\"payment_context_id\""));
+        assertFalse(json.contains("\"previous_payment_id\""));
+        assertFalse(json.contains("\"success_url\""));
+        assertFalse(json.contains("\"failure_url\""));
+        assertFalse(json.contains("\"merchant_initiated\""));
+    }
+
+    @Test
+    void shouldHandleAbsentOptionalFields() {
+        final String json = "{\"currency\":\"USD\"}";
+
+        final PaymentRequest request = serializer.fromJson(json, PaymentRequest.class);
+
+        assertNotNull(request);
+        assertDoesNotThrow(() -> serializer.toJson(request));
+        assertNull(request.getPaymentContextId());
+        assertNull(request.getAmount());
+        assertNull(request.getMerchantInitiated());
+        assertNull(request.getPreviousPaymentId());
+    }
+}
diff --git a/src/test/java/com/checkout/payments/request/PaymentRetryRequestSerializationTest.java b/src/test/java/com/checkout/payments/request/PaymentRetryRequestSerializationTest.java
new file mode 100644
index 00000000..2922a5ad
--- /dev/null
+++ b/src/test/java/com/checkout/payments/request/PaymentRetryRequestSerializationTest.java
@@ -0,0 +1,126 @@
+package com.checkout.payments.request;
+
+import com.checkout.GsonSerializer;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class PaymentRetryRequestSerializationTest {
+
+    private final GsonSerializer serializer = new GsonSerializer();
+
+    @Test
+    void shouldSerializeWithDunningConfig() {
+        final PaymentRetryRequest request = PaymentRetryRequest.builder()
+                .dunning(DunningRetryRequest.builder()
+                        .enabled(true)
+                        .maxAttempts(3)
+                        .endAfterDays(7)
+                        .build())
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertNotNull(json);
+        assertTrue(json.contains("\"dunning\""));
+        assertTrue(json.contains("\"enabled\":true"));
+        assertTrue(json.contains("\"max_attempts\":3"));
+        assertTrue(json.contains("\"end_after_days\":7"));
+    }
+
+    @Test
+    void shouldSerializeWithDowntimeConfig() {
+        final PaymentRetryRequest request = PaymentRetryRequest.builder()
+                .downtime(DowntimeRetryRequest.builder()
+                        .enabled(true)
+                        .build())
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertNotNull(json);
+        assertTrue(json.contains("\"downtime\""));
+        assertTrue(json.contains("\"enabled\":true"));
+    }
+
+    @Test
+    void shouldSerializeWithBothDunningAndDowntime() {
+        final PaymentRetryRequest request = PaymentRetryRequest.builder()
+                .dunning(DunningRetryRequest.builder()
+                        .enabled(true)
+                        .maxAttempts(5)
+                        .endAfterDays(14)
+                        .build())
+                .downtime(DowntimeRetryRequest.builder()
+                        .enabled(false)
+                        .build())
+                .build();
+
+        assertDoesNotThrow(() -> serializer.toJson(request));
+    }
+
+    @Test
+    void shouldDeserializeDunningFromJson() {
+        final String json = "{"
+                + "\"dunning\":{"
+                + "  \"enabled\":true,"
+                + "  \"max_attempts\":3,"
+                + "  \"end_after_days\":7"
+                + "},"
+                + "\"downtime\":{"
+                + "  \"enabled\":false"
+                + "}"
+                + "}";
+
+        final PaymentRetryRequest request = serializer.fromJson(json, PaymentRetryRequest.class);
+
+        assertNotNull(request);
+        assertNotNull(request.getDunning());
+        assertTrue(request.getDunning().getEnabled());
+        assertEquals(3, request.getDunning().getMaxAttempts());
+        assertEquals(7, request.getDunning().getEndAfterDays());
+        assertNotNull(request.getDowntime());
+        assertEquals(false, request.getDowntime().getEnabled());
+    }
+
+    @Test
+    void shouldRoundTripSerialize() {
+        final PaymentRetryRequest original = PaymentRetryRequest.builder()
+                .dunning(DunningRetryRequest.builder()
+                        .enabled(true)
+                        .maxAttempts(3)
+                        .endAfterDays(7)
+                        .build())
+                .downtime(DowntimeRetryRequest.builder()
+                        .enabled(true)
+                        .build())
+                .build();
+
+        final String json = serializer.toJson(original);
+        final PaymentRetryRequest deserialized = serializer.fromJson(json, PaymentRetryRequest.class);
+
+        assertNotNull(deserialized);
+        assertNotNull(deserialized.getDunning());
+        assertEquals(true, deserialized.getDunning().getEnabled());
+        assertEquals(3, deserialized.getDunning().getMaxAttempts());
+        assertEquals(7, deserialized.getDunning().getEndAfterDays());
+        assertNotNull(deserialized.getDowntime());
+        assertEquals(true, deserialized.getDowntime().getEnabled());
+    }
+
+    @Test
+    void shouldHandleAbsentOptionalFields() {
+        final String json = "{}";
+
+        final PaymentRetryRequest request = serializer.fromJson(json, PaymentRetryRequest.class);
+
+        assertNotNull(request);
+        assertDoesNotThrow(() -> serializer.toJson(request));
+        assertNull(request.getDunning());
+        assertNull(request.getDowntime());
+    }
+}
diff --git a/src/test/java/com/checkout/payments/request/PayoutRequestSerializationTest.java b/src/test/java/com/checkout/payments/request/PayoutRequestSerializationTest.java
new file mode 100644
index 00000000..7f1a7aeb
--- /dev/null
+++ b/src/test/java/com/checkout/payments/request/PayoutRequestSerializationTest.java
@@ -0,0 +1,156 @@
+package com.checkout.payments.request;
+
+import com.checkout.GsonSerializer;
+import com.checkout.common.Currency;
+import com.checkout.payments.request.source.PayoutRequestCurrencyAccountSource;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class PayoutRequestSerializationTest {
+
+    private final GsonSerializer serializer = new GsonSerializer();
+
+    @Test
+    void shouldSerializeCurrencyAndAmount() {
+        final PayoutRequest request = PayoutRequest.builder()
+                .currency(Currency.USD)
+                .amount(5000L)
+                .source(PayoutRequestCurrencyAccountSource.builder().id("ca_abc123").build())
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertNotNull(json);
+        assertTrue(json.contains("\"currency\":\"USD\""));
+        assertTrue(json.contains("\"amount\":5000"));
+    }
+
+    @Test
+    void shouldSerializeReference() {
+        final PayoutRequest request = PayoutRequest.builder()
+                .currency(Currency.GBP)
+                .reference("PO-2024-001")
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertTrue(json.contains("\"reference\":\"PO-2024-001\""));
+    }
+
+    @Test
+    void shouldSerializeProcessingChannelId() {
+        final PayoutRequest request = PayoutRequest.builder()
+                .currency(Currency.EUR)
+                .processingChannelId("pc_abcdefghijklmnopqrstuvwxyz")
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertTrue(json.contains("\"processing_channel_id\":\"pc_abcdefghijklmnopqrstuvwxyz\""));
+    }
+
+    @Test
+    void shouldSerializeBillingDescriptor() {
+        final PayoutRequest request = PayoutRequest.builder()
+                .currency(Currency.USD)
+                .billingDescriptor(PayoutBillingDescriptor.builder()
+                        .reference("Payout reference")
+                        .build())
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertTrue(json.contains("\"billing_descriptor\""));
+        assertTrue(json.contains("\"reference\":\"Payout reference\""));
+    }
+
+    @Test
+    void shouldSerializeInstruction() {
+        final PayoutRequest request = PayoutRequest.builder()
+                .currency(Currency.USD)
+                .instruction(PaymentInstruction.builder()
+                        .purpose("salary")
+                        .build())
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertTrue(json.contains("\"instruction\""));
+        assertTrue(json.contains("\"purpose\":\"salary\""));
+    }
+
+    @Test
+    void shouldDeserializeKeyFields() {
+        final String json = "{"
+                + "\"amount\":10000,"
+                + "\"currency\":\"GBP\","
+                + "\"reference\":\"PO-001\","
+                + "\"processing_channel_id\":\"pc_test\""
+                + "}";
+
+        final PayoutRequest request = serializer.fromJson(json, PayoutRequest.class);
+
+        assertNotNull(request);
+        assertEquals(10000L, request.getAmount());
+        assertEquals(Currency.GBP, request.getCurrency());
+        assertEquals("PO-001", request.getReference());
+        assertEquals("pc_test", request.getProcessingChannelId());
+    }
+
+    @Test
+    void shouldRoundTripSerialize() {
+        final PayoutRequest original = PayoutRequest.builder()
+                .currency(Currency.EUR)
+                .amount(7500L)
+                .reference("RT-PAYOUT-001")
+                .processingChannelId("pc_abcdefghijklmnopqrstuvwxyz")
+                .billingDescriptor(PayoutBillingDescriptor.builder()
+                        .reference("RT descriptor")
+                        .build())
+                .build();
+
+        final String json = serializer.toJson(original);
+        final PayoutRequest deserialized = serializer.fromJson(json, PayoutRequest.class);
+
+        assertNotNull(deserialized);
+        assertEquals(Currency.EUR, deserialized.getCurrency());
+        assertEquals(7500L, deserialized.getAmount());
+        assertEquals("RT-PAYOUT-001", deserialized.getReference());
+        assertEquals("pc_abcdefghijklmnopqrstuvwxyz", deserialized.getProcessingChannelId());
+        assertNotNull(deserialized.getBillingDescriptor());
+        assertEquals("RT descriptor", deserialized.getBillingDescriptor().getReference());
+    }
+
+    @Test
+    void shouldNotSerializeNullOptionalFields() {
+        final PayoutRequest request = PayoutRequest.builder()
+                .currency(Currency.USD)
+                .build();
+
+        final String json = serializer.toJson(request);
+
+        assertFalse(json.contains("\"amount\""));
+        assertFalse(json.contains("\"reference\""));
+        assertFalse(json.contains("\"billing_descriptor\""));
+        assertFalse(json.contains("\"processing_channel_id\""));
+    }
+
+    @Test
+    void shouldHandleAbsentOptionalFields() {
+        final String json = "{\"currency\":\"USD\"}";
+
+        final PayoutRequest request = serializer.fromJson(json, PayoutRequest.class);
+
+        assertNotNull(request);
+        assertDoesNotThrow(() -> serializer.toJson(request));
+        assertNull(request.getAmount());
+        assertNull(request.getReference());
+        assertNull(request.getBillingDescriptor());
+    }
+}
diff --git a/src/test/java/com/checkout/payments/request/source/RequestCustomerSourceSerializationTest.java b/src/test/java/com/checkout/payments/request/source/RequestCustomerSourceSerializationTest.java
new file mode 100644
index 00000000..73ec0652
--- /dev/null
+++ b/src/test/java/com/checkout/payments/request/source/RequestCustomerSourceSerializationTest.java
@@ -0,0 +1,148 @@
+package com.checkout.payments.request.source;
+
+import com.checkout.GsonSerializer;
+import com.checkout.common.AccountHolder;
+import com.checkout.common.Address;
+import com.checkout.common.CountryCode;
+import com.checkout.common.Phone;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class RequestCustomerSourceSerializationTest {
+
+    private final GsonSerializer serializer = new GsonSerializer();
+
+    @Test
+    void shouldSerializeWithCustomerId() {
+        final RequestCustomerSource source = RequestCustomerSource.builder()
+                .id("cus_y3oqhf46pyzuxjbcn2giaqnb44")
+                .build();
+
+        final String json = serializer.toJson(source);
+
+        assertNotNull(json);
+        assertTrue(json.contains("\"type\":\"customer\""));
+        assertTrue(json.contains("\"id\":\"cus_y3oqhf46pyzuxjbcn2giaqnb44\""));
+    }
+
+    @Test
+    void shouldSerializeWithAllOptionalFields() {
+        final RequestCustomerSource source = RequestCustomerSource.builder()
+                .id("cus_y3oqhf46pyzuxjbcn2giaqnb44")
+                .billingAddress(Address.builder()
+                        .addressLine1("123 High Street")
+                        .city("London")
+                        .zip("SW1A 1AA")
+                        .country(CountryCode.GB)
+                        .build())
+                .phone(Phone.builder()
+                        .countryCode("+44")
+                        .number("7911123456")
+                        .build())
+                .accountHolder(AccountHolder.builder()
+                        .firstName("John")
+                        .lastName("Smith")
+                        .build())
+                .allowUpdate(true)
+                .build();
+
+        assertDoesNotThrow(() -> serializer.toJson(source));
+    }
+
+    @Test
+    void shouldSerializeBillingAddress() {
+        final RequestCustomerSource source = RequestCustomerSource.builder()
+                .id("cus_y3oqhf46pyzuxjbcn2giaqnb44")
+                .billingAddress(Address.builder()
+                        .addressLine1("123 High Street")
+                        .country(CountryCode.GB)
+                        .build())
+                .build();
+
+        final String json = serializer.toJson(source);
+
+        assertTrue(json.contains("\"billing_address\""));
+        assertTrue(json.contains("\"address_line1\":\"123 High Street\""));
+    }
+
+    @Test
+    void shouldSerializeAllowUpdate() {
+        final RequestCustomerSource source = RequestCustomerSource.builder()
+                .id("cus_y3oqhf46pyzuxjbcn2giaqnb44")
+                .allowUpdate(true)
+                .build();
+
+        final String json = serializer.toJson(source);
+
+        assertTrue(json.contains("\"allow_update\":true"));
+    }
+
+    @Test
+    void shouldDeserializeSwaggerExample() {
+        final String swaggerJson = "{"
+                + "\"type\":\"customer\","
+                + "\"id\":\"cus_y3oqhf46pyzuxjbcn2giaqnb44\","
+                + "\"billing_address\":{"
+                + "  \"address_line1\":\"123 High Street\","
+                + "  \"city\":\"London\","
+                + "  \"zip\":\"SW1A 1AA\","
+                + "  \"country\":\"GB\""
+                + "},"
+                + "\"phone\":{"
+                + "  \"country_code\":\"+44\","
+                + "  \"number\":\"7911123456\""
+                + "},"
+                + "\"allow_update\":true"
+                + "}";
+
+        final RequestCustomerSource source = serializer.fromJson(swaggerJson, RequestCustomerSource.class);
+
+        assertNotNull(source);
+        assertEquals("cus_y3oqhf46pyzuxjbcn2giaqnb44", source.getId());
+        assertNotNull(source.getBillingAddress());
+        assertEquals("123 High Street", source.getBillingAddress().getAddressLine1());
+        assertNotNull(source.getPhone());
+        assertEquals("+44", source.getPhone().getCountryCode());
+        assertTrue(source.getAllowUpdate());
+    }
+
+    @Test
+    void shouldRoundTripSerialize() {
+        final RequestCustomerSource original = RequestCustomerSource.builder()
+                .id("cus_y3oqhf46pyzuxjbcn2giaqnb44")
+                .billingAddress(Address.builder()
+                        .addressLine1("123 High Street")
+                        .country(CountryCode.GB)
+                        .build())
+                .allowUpdate(true)
+                .build();
+
+        final String json = serializer.toJson(original);
+        final RequestCustomerSource deserialized = serializer.fromJson(json, RequestCustomerSource.class);
+
+        assertNotNull(deserialized);
+        assertEquals("cus_y3oqhf46pyzuxjbcn2giaqnb44", deserialized.getId());
+        assertNotNull(deserialized.getBillingAddress());
+        assertEquals("123 High Street", deserialized.getBillingAddress().getAddressLine1());
+        assertTrue(deserialized.getAllowUpdate());
+    }
+
+    @Test
+    void shouldHandleAbsentOptionalFields() {
+        final String json = "{\"type\":\"customer\",\"id\":\"cus_y3oqhf46pyzuxjbcn2giaqnb44\"}";
+
+        final RequestCustomerSource source = serializer.fromJson(json, RequestCustomerSource.class);
+
+        assertNotNull(source);
+        assertDoesNotThrow(() -> serializer.toJson(source));
+        assertNull(source.getBillingAddress());
+        assertNull(source.getPhone());
+        assertNull(source.getAccountHolder());
+        assertNull(source.getAllowUpdate());
+    }
+}
diff --git a/src/test/java/com/checkout/payments/request/source/RequestIdSourceSerializationTest.java b/src/test/java/com/checkout/payments/request/source/RequestIdSourceSerializationTest.java
new file mode 100644
index 00000000..01dcd223
--- /dev/null
+++ b/src/test/java/com/checkout/payments/request/source/RequestIdSourceSerializationTest.java
@@ -0,0 +1,172 @@
+package com.checkout.payments.request.source;
+
+import com.checkout.GsonSerializer;
+import com.checkout.common.AccountHolder;
+import com.checkout.common.Address;
+import com.checkout.common.CountryCode;
+import com.checkout.common.Phone;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class RequestIdSourceSerializationTest {
+
+    private final GsonSerializer serializer = new GsonSerializer();
+
+    @Test
+    void shouldSerializeWithRequiredId() {
+        final RequestIdSource source = RequestIdSource.builder()
+                .id("src_wmlfc3zyhqzehihu7giusaaawu")
+                .build();
+
+        final String json = serializer.toJson(source);
+
+        assertNotNull(json);
+        assertTrue(json.contains("\"type\":\"id\""));
+        assertTrue(json.contains("\"id\":\"src_wmlfc3zyhqzehihu7giusaaawu\""));
+    }
+
+    @Test
+    void shouldSerializeWithAllOptionalFields() {
+        final RequestIdSource source = RequestIdSource.builder()
+                .id("src_wmlfc3zyhqzehihu7giusaaawu")
+                .cvv("100")
+                .paymentMethod("visa")
+                .stored(true)
+                .storeForFutureUse(false)
+                .billingAddress(Address.builder()
+                        .addressLine1("123 High Street")
+                        .city("London")
+                        .zip("SW1A 1AA")
+                        .country(CountryCode.GB)
+                        .build())
+                .phone(Phone.builder()
+                        .countryCode("+44")
+                        .number("7911123456")
+                        .build())
+                .accountHolder(AccountHolder.builder()
+                        .firstName("John")
+                        .lastName("Smith")
+                        .build())
+                .allowUpdate(true)
+                .build();
+
+        assertDoesNotThrow(() -> serializer.toJson(source));
+    }
+
+    @Test
+    void shouldSerializeBillingAddress() {
+        final RequestIdSource source = RequestIdSource.builder()
+                .id("src_wmlfc3zyhqzehihu7giusaaawu")
+                .billingAddress(Address.builder()
+                        .addressLine1("123 High Street")
+                        .country(CountryCode.GB)
+                        .build())
+                .build();
+
+        final String json = serializer.toJson(source);
+
+        assertTrue(json.contains("\"billing_address\""));
+        assertTrue(json.contains("\"address_line1\":\"123 High Street\""));
+    }
+
+    @Test
+    void shouldSerializeAllowUpdate() {
+        final RequestIdSource source = RequestIdSource.builder()
+                .id("src_wmlfc3zyhqzehihu7giusaaawu")
+                .allowUpdate(true)
+                .build();
+
+        final String json = serializer.toJson(source);
+
+        assertTrue(json.contains("\"allow_update\":true"));
+    }
+
+    @Test
+    void shouldSerializeStoreForFutureUse() {
+        final RequestIdSource source = RequestIdSource.builder()
+                .id("src_wmlfc3zyhqzehihu7giusaaawu")
+                .storeForFutureUse(true)
+                .build();
+
+        final String json = serializer.toJson(source);
+
+        assertTrue(json.contains("\"store_for_future_use\":true"));
+    }
+
+    @Test
+    void shouldDeserializeSwaggerExample() {
+        final String swaggerJson = "{"
+                + "\"type\":\"id\","
+                + "\"id\":\"src_wmlfc3zyhqzehihu7giusaaawu\","
+                + "\"cvv\":\"100\","
+                + "\"stored\":false,"
+                + "\"billing_address\":{"
+                + "  \"address_line1\":\"123 High Street\","
+                + "  \"city\":\"London\","
+                + "  \"zip\":\"SW1A 1AA\","
+                + "  \"country\":\"GB\""
+                + "},"
+                + "\"phone\":{"
+                + "  \"country_code\":\"+44\","
+                + "  \"number\":\"7911123456\""
+                + "},"
+                + "\"allow_update\":false"
+                + "}";
+
+        final RequestIdSource source = serializer.fromJson(swaggerJson, RequestIdSource.class);
+
+        assertNotNull(source);
+        assertEquals("src_wmlfc3zyhqzehihu7giusaaawu", source.getId());
+        assertEquals("100", source.getCvv());
+        assertEquals(false, source.getStored());
+        assertNotNull(source.getBillingAddress());
+        assertEquals("123 High Street", source.getBillingAddress().getAddressLine1());
+        assertEquals(CountryCode.GB, source.getBillingAddress().getCountry());
+        assertNotNull(source.getPhone());
+        assertEquals("+44", source.getPhone().getCountryCode());
+        assertEquals(false, source.getAllowUpdate());
+    }
+
+    @Test
+    void shouldRoundTripSerialize() {
+        final RequestIdSource original = RequestIdSource.builder()
+                .id("src_wmlfc3zyhqzehihu7giusaaawu")
+                .cvv("100")
+                .stored(true)
+                .billingAddress(Address.builder()
+                        .addressLine1("123 High Street")
+                        .country(CountryCode.GB)
+                        .build())
+                .allowUpdate(true)
+                .build();
+
+        final String json = serializer.toJson(original);
+        final RequestIdSource deserialized = serializer.fromJson(json, RequestIdSource.class);
+
+        assertNotNull(deserialized);
+        assertEquals("src_wmlfc3zyhqzehihu7giusaaawu", deserialized.getId());
+        assertEquals("100", deserialized.getCvv());
+        assertTrue(deserialized.getStored());
+        assertNotNull(deserialized.getBillingAddress());
+        assertTrue(deserialized.getAllowUpdate());
+    }
+
+    @Test
+    void shouldHandleAbsentOptionalFields() {
+        final String json = "{\"type\":\"id\",\"id\":\"src_wmlfc3zyhqzehihu7giusaaawu\"}";
+
+        final RequestIdSource source = serializer.fromJson(json, RequestIdSource.class);
+
+        assertNotNull(source);
+        assertDoesNotThrow(() -> serializer.toJson(source));
+        assertNull(source.getCvv());
+        assertNull(source.getBillingAddress());
+        assertNull(source.getPhone());
+        assertNull(source.getAllowUpdate());
+    }
+}
diff --git a/src/test/java/com/checkout/payments/request/source/apm/RequestSepaSourceSerializationTest.java b/src/test/java/com/checkout/payments/request/source/apm/RequestSepaSourceSerializationTest.java
new file mode 100644
index 00000000..e717e5e3
--- /dev/null
+++ b/src/test/java/com/checkout/payments/request/source/apm/RequestSepaSourceSerializationTest.java
@@ -0,0 +1,170 @@
+package com.checkout.payments.request.source.apm;
+
+import com.checkout.GsonSerializer;
+import com.checkout.common.AccountHolder;
+import com.checkout.common.AccountHolderType;
+import com.checkout.common.Address;
+import com.checkout.common.CountryCode;
+import com.checkout.common.Currency;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class RequestSepaSourceSerializationTest {
+
+    private final GsonSerializer serializer = new GsonSerializer();
+
+    @Test
+    void shouldSerializeWithRequiredFields() {
+        final RequestSepaSource source = RequestSepaSource.builder()
+                .country(CountryCode.FR)
+                .accountNumber("FR7630006000011234567890189")
+                .currency(Currency.EUR)
+                .accountHolder(AccountHolder.builder()
+                        .firstName("John")
+                        .lastName("Smith")
+                        .billingAddress(Address.builder()
+                                .addressLine1("123 Rue de la Paix")
+                                .city("Paris")
+                                .zip("75000")
+                                .country(CountryCode.FR)
+                                .build())
+                        .build())
+                .build();
+
+        assertDoesNotThrow(() -> serializer.toJson(source));
+    }
+
+    @Test
+    void shouldSerializeWithAllOptionalFields() {
+        final RequestSepaSource source = RequestSepaSource.builder()
+                .country(CountryCode.FR)
+                .accountNumber("FR7630006000011234567890189")
+                .currency(Currency.EUR)
+                .mandateId("123456")
+                .mandateType(MandateType.B2B)
+                .dateOfSignature("2022-08-02")
+                .accountHolder(AccountHolder.builder()
+                        .type(AccountHolderType.CORPORATE)
+                        .firstName("John")
+                        .lastName("Smith")
+                        .companyName("Acme Corp")
+                        .billingAddress(Address.builder()
+                                .addressLine1("123 Rue de la Paix")
+                                .city("Paris")
+                                .zip("75000")
+                                .country(CountryCode.FR)
+                                .build())
+                        .build())
+                .build();
+
+        assertDoesNotThrow(() -> serializer.toJson(source));
+    }
+
+    @Test
+    void shouldSerializeMandateTypeB2B() {
+        final RequestSepaSource source = RequestSepaSource.builder()
+                .country(CountryCode.FR)
+                .accountNumber("FR7630006000011234567890189")
+                .currency(Currency.EUR)
+                .mandateType(MandateType.B2B)
+                .accountHolder(AccountHolder.builder()
+                        .firstName("John")
+                        .lastName("Smith")
+                        .billingAddress(Address.builder()
+                                .country(CountryCode.FR).build())
+                        .build())
+                .build();
+
+        final String json = serializer.toJson(source);
+
+        assertTrue(json.contains("\"mandate_type\":\"B2B\""),
+                "mandate_type should serialize as 'B2B'. Got: " + json);
+    }
+
+    @Test
+    void shouldSerializeMandateTypeCore() {
+        final RequestSepaSource source = RequestSepaSource.builder()
+                .country(CountryCode.FR)
+                .accountNumber("FR7630006000011234567890189")
+                .currency(Currency.EUR)
+                .mandateType(MandateType.CORE)
+                .accountHolder(AccountHolder.builder()
+                        .firstName("John")
+                        .lastName("Smith")
+                        .billingAddress(Address.builder()
+                                .country(CountryCode.FR).build())
+                        .build())
+                .build();
+
+        final String json = serializer.toJson(source);
+
+        assertTrue(json.contains("\"mandate_type\":\"Core\""),
+                "mandate_type should serialize as 'Core'. Got: " + json);
+    }
+
+    @Test
+    void shouldRoundTripSerialize() {
+        final RequestSepaSource original = RequestSepaSource.builder()
+                .country(CountryCode.FR)
+                .accountNumber("FR7630006000011234567890189")
+                .currency(Currency.EUR)
+                .mandateId("123456")
+                .mandateType(MandateType.B2B)
+                .dateOfSignature("2022-08-02")
+                .accountHolder(AccountHolder.builder()
+                        .firstName("John")
+                        .lastName("Smith")
+                        .billingAddress(Address.builder()
+                                .country(CountryCode.FR).build())
+                        .build())
+                .build();
+
+        final String json = serializer.toJson(original);
+        final RequestSepaSource deserialized = serializer.fromJson(json, RequestSepaSource.class);
+
+        assertNotNull(deserialized);
+        assertEquals(CountryCode.FR, deserialized.getCountry());
+        assertEquals("FR7630006000011234567890189", deserialized.getAccountNumber());
+        assertEquals(MandateType.B2B, deserialized.getMandateType());
+        assertEquals("123456", deserialized.getMandateId());
+    }
+
+    @Test
+    void shouldDeserializeSwaggerExample() {
+        final String swaggerJson = "{"
+                + "\"type\":\"sepa\","
+                + "\"country\":\"FR\","
+                + "\"account_number\":\"FR7630006000011234567890189\","
+                + "\"currency\":\"EUR\","
+                + "\"mandate_id\":\"123456\","
+                + "\"mandate_type\":\"B2B\","
+                + "\"date_of_signature\":\"2022-08-02\","
+                + "\"account_holder\":{"
+                + "  \"first_name\":\"John\","
+                + "  \"last_name\":\"Wick\","
+                + "  \"type\":\"Corporate\","
+                + "  \"company_name\":\"Checkout.com\","
+                + "  \"billing_address\":{"
+                + "    \"address_line1\":\"Evergreen Terrace\","
+                + "    \"address_line2\":\"742\","
+                + "    \"city\":\"Paris\","
+                + "    \"zip\":\"75000\","
+                + "    \"country\":\"FR\""
+                + "  }"
+                + "}"
+                + "}";
+
+        final RequestSepaSource source = serializer.fromJson(swaggerJson, RequestSepaSource.class);
+
+        assertNotNull(source);
+        assertEquals(CountryCode.FR, source.getCountry());
+        assertEquals("FR7630006000011234567890189", source.getAccountNumber());
+        assertEquals(MandateType.B2B, source.getMandateType());
+        assertNotNull(source.getAccountHolder());
+        assertEquals("John", source.getAccountHolder().getFirstName());
+    }
+}
diff --git a/src/test/java/com/checkout/payments/response/source/PayPalResponseSourceSerializationTest.java b/src/test/java/com/checkout/payments/response/source/PayPalResponseSourceSerializationTest.java
new file mode 100644
index 00000000..2864b92a
--- /dev/null
+++ b/src/test/java/com/checkout/payments/response/source/PayPalResponseSourceSerializationTest.java
@@ -0,0 +1,98 @@
+package com.checkout.payments.response.source;
+
+import com.checkout.GsonSerializer;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
+
+class PayPalResponseSourceSerializationTest {
+
+    private final GsonSerializer serializer = new GsonSerializer();
+
+    @Test
+    void shouldDeserializeWithAccountHolder() {
+        final String json = "{"
+                + "\"type\":\"paypal\","
+                + "\"account_holder\":{"
+                + "  \"email\":\"john.smith@example.com\","
+                + "  \"full_name\":\"John Smith\""
+                + "}"
+                + "}";
+
+        final PayPalResponseSource source = serializer.fromJson(json, PayPalResponseSource.class);
+
+        assertNotNull(source);
+        assertNotNull(source.getAccountHolder());
+        assertEquals("john.smith@example.com", source.getAccountHolder().getEmail());
+        assertEquals("John Smith", source.getAccountHolder().getFullName());
+    }
+
+    @Test
+    void shouldDeserializeWithEmailOnly() {
+        final String json = "{"
+                + "\"type\":\"paypal\","
+                + "\"account_holder\":{"
+                + "  \"email\":\"buyer@example.com\""
+                + "}"
+                + "}";
+
+        final PayPalResponseSource source = serializer.fromJson(json, PayPalResponseSource.class);
+
+        assertNotNull(source);
+        assertNotNull(source.getAccountHolder());
+        assertEquals("buyer@example.com", source.getAccountHolder().getEmail());
+        assertNull(source.getAccountHolder().getFullName());
+    }
+
+    @Test
+    void shouldDeserializeSwaggerExample() {
+        final String swaggerJson = "{"
+                + "\"type\":\"paypal\","
+                + "\"account_holder\":{"
+                + "  \"email\":\"payer@example.com\","
+                + "  \"full_name\":\"Jane Doe\""
+                + "}"
+                + "}";
+
+        final PayPalResponseSource source = serializer.fromJson(swaggerJson, PayPalResponseSource.class);
+
+        assertNotNull(source);
+        assertNotNull(source.getAccountHolder());
+        assertEquals("payer@example.com", source.getAccountHolder().getEmail());
+        assertEquals("Jane Doe", source.getAccountHolder().getFullName());
+    }
+
+    @Test
+    void shouldRoundTripSerialize() {
+        final String original = "{"
+                + "\"type\":\"paypal\","
+                + "\"account_holder\":{"
+                + "  \"email\":\"john.smith@example.com\","
+                + "  \"full_name\":\"John Smith\""
+                + "}"
+                + "}";
+
+        final PayPalResponseSource source = serializer.fromJson(original, PayPalResponseSource.class);
+        final String reserialised = serializer.toJson(source);
+        final PayPalResponseSource roundTripped = serializer.fromJson(reserialised, PayPalResponseSource.class);
+
+        assertNotNull(roundTripped);
+        assertNotNull(roundTripped.getAccountHolder());
+        assertEquals("john.smith@example.com", roundTripped.getAccountHolder().getEmail());
+        assertEquals("John Smith", roundTripped.getAccountHolder().getFullName());
+    }
+
+    @Test
+    void shouldHandleAbsentOptionalFields() {
+        final String json = "{\"type\":\"paypal\"}";
+
+        final PayPalResponseSource source = serializer.fromJson(json, PayPalResponseSource.class);
+
+        assertNotNull(source);
+        assertDoesNotThrow(() -> serializer.toJson(source));
+        assertNull(source.getAccountHolder());
+    }
+}