diff --git a/apps/start/src/routes/_login.login.tsx b/apps/start/src/routes/_login.login.tsx
index ef36777ed..89c7c7e0b 100644
--- a/apps/start/src/routes/_login.login.tsx
+++ b/apps/start/src/routes/_login.login.tsx
@@ -9,6 +9,11 @@ import { Alert, AlertDescription, AlertTitle } from '@/components/ui/alert';
 import { useCookieStore } from '@/hooks/use-cookie-store';
 import { createTitle, PAGE_TITLES } from '@/utils/title';
 
+const validateSearch = z.object({
+  error: z.string().optional(),
+  correlationId: z.string().optional(),
+  inviteId: z.string().optional(),
+});
 export const Route = createFileRoute('/_login/login')({
   component: LoginPage,
   head: () => ({
@@ -17,15 +22,20 @@ export const Route = createFileRoute('/_login/login')({
       { name: 'robots', content: 'noindex, follow' },
     ],
   }),
-  validateSearch: z.object({
-    error: z.string().optional(),
-    correlationId: z.string().optional(),
-    inviteId: z.string().optional(),
-  }),
+  validateSearch,
+  loader: ({ context, location }) => {
+    const search = validateSearch.safeParse(location.search);
+    return context.queryClient.ensureQueryData(
+      context.trpc.auth.isRegistrationAllowed.queryOptions({
+        inviteId: search.success ? search.data.inviteId : undefined,
+      })
+    );
+  },
 });
 
 function LoginPage() {
   const { error, correlationId, inviteId } = Route.useSearch();
+  const isRegistrationAllowed = Route.useLoaderData();
   const [lastProvider] = useCookieStore<null | string>(
     'last-auth-provider',
     null
@@ -35,15 +45,21 @@ function LoginPage() {
     <div className="col w-full gap-8 text-left">
       <div>
         <h1 className="mb-2 font-bold text-3xl text-foreground">Sign in</h1>
-        <p className="text-muted-foreground">
-          Don't have an account?{' '}
-          <a
-            className="font-medium text-foreground underline"
-            href="/onboarding"
-          >
-            Create one today
-          </a>
-        </p>
+        {isRegistrationAllowed && (
+          <p className="text-muted-foreground">
+            Don't have an account?{' '}
+            <a
+              className="font-medium text-foreground underline"
+              href={
+                inviteId
+                  ? `/onboarding?inviteId=${encodeURIComponent(inviteId)}`
+                  : '/onboarding'
+              }
+            >
+              Create one today
+            </a>
+          </p>
+        )}
       </div>
       {error && (
         <Alert
diff --git a/apps/start/src/routes/_public.onboarding.tsx b/apps/start/src/routes/_public.onboarding.tsx
index e854db824..c8617e4ae 100644
--- a/apps/start/src/routes/_public.onboarding.tsx
+++ b/apps/start/src/routes/_public.onboarding.tsx
@@ -36,12 +36,18 @@ export const Route = createFileRoute('/_public/onboarding')({
         })
       );
     }
+    return context.queryClient.ensureQueryData(
+      context.trpc.auth.isRegistrationAllowed.queryOptions({
+        inviteId: search.success ? search.data.inviteId : undefined,
+      })
+    );
   },
   pendingComponent: FullPageLoadingState,
 });
 
 function Component() {
   const { inviteId } = Route.useSearch();
+  const isRegistrationAllowed = Route.useLoaderData();
   const trpc = useTRPC();
   const { data: invite } = useQuery(
     trpc.organization.getInvite.queryOptions(
@@ -53,6 +59,32 @@ function Component() {
       }
     )
   );
+
+  if (!isRegistrationAllowed) {
+    return (
+      <div className="col w-full gap-8 py-4 text-left">
+        <div>
+          <h1 className="mb-2 font-bold text-3xl text-foreground">
+            {inviteId
+              ? 'Registration is unavailable'
+              : 'Registration is disabled'}
+          </h1>
+          <p className="text-muted-foreground">
+            {inviteId
+              ? 'This invitation no longer exists, has already been used, or invitations are disabled on this instance. Ask an administrator for help.'
+              : "New accounts can't be created on this instance. Ask an administrator to invite you."}
+          </p>
+          <p className="mt-3 text-muted-foreground">
+            Already have an account?{' '}
+            <a className="font-medium text-foreground underline" href="/login">
+              Sign in
+            </a>
+          </p>
+        </div>
+      </div>
+    );
+  }
+
   return (
     <div className="col w-full gap-8 py-4 text-left">
       <div>
diff --git a/packages/trpc/src/routers/auth.ts b/packages/trpc/src/routers/auth.ts
index 5f7dec314..bd6252b87 100644
--- a/packages/trpc/src/routers/auth.ts
+++ b/packages/trpc/src/routers/auth.ts
@@ -589,6 +589,11 @@ export const authRouter = createTRPCRouter({
     return ctx.session;
   }),
 
+  // Lets the login/onboarding pages hide sign-up when it would be rejected.
+  isRegistrationAllowed: publicProcedure
+    .input(z.object({ inviteId: z.string().nullish() }))
+    .query(({ input }) => getIsRegistrationAllowed(input.inviteId)),
+
   extendSession: publicProcedure.mutation(async ({ ctx }) => {
     if (!(ctx.session.session && ctx.cookies.session)) {
       return { extended: false };