diff --git a/.changeset/tidy-signout-flow.md b/.changeset/tidy-signout-flow.md
new file mode 100644
index 00000000000..ad9a0c0dfb6
--- /dev/null
+++ b/.changeset/tidy-signout-flow.md
@@ -0,0 +1,6 @@
+---
+'@clerk/clerk-js': patch
+'@clerk/shared': patch
+---
+
+Treat terminal user-state 403 responses as unauthenticated in ClerkJS.
diff --git a/packages/shared/src/__tests__/error.spec.ts b/packages/shared/src/__tests__/error.spec.ts
index b4d21e8e45d..47981be4a4e 100644
--- a/packages/shared/src/__tests__/error.spec.ts
+++ b/packages/shared/src/__tests__/error.spec.ts
@@ -108,9 +108,15 @@ describe('isUnauthenticatedError', () => {
     expect(isUnauthenticatedError({ status: 422 })).toBe(true);
   });
 
+  it('returns true for terminal user state 403 errors', () => {
+    expect(isUnauthenticatedError({ status: 403, errors: [{ code: 'user_banned' }] })).toBe(true);
+    expect(isUnauthenticatedError({ status: 403, errors: [{ code: 'user_deactivated' }] })).toBe(true);
+  });
+
   it('returns false for other 4xx status codes', () => {
     expect(isUnauthenticatedError({ status: 400 })).toBe(false);
     expect(isUnauthenticatedError({ status: 403 })).toBe(false);
+    expect(isUnauthenticatedError({ status: 403, errors: [{ code: 'not_allowed_access' }] })).toBe(false);
     expect(isUnauthenticatedError({ status: 404 })).toBe(false);
     expect(isUnauthenticatedError({ status: 429 })).toBe(false);
   });
diff --git a/packages/shared/src/errors/helpers.ts b/packages/shared/src/errors/helpers.ts
index 93d22ef627b..1aeb4c698d7 100644
--- a/packages/shared/src/errors/helpers.ts
+++ b/packages/shared/src/errors/helpers.ts
@@ -46,6 +46,8 @@ export function is429Error(e: any): boolean {
   return e?.status === 429;
 }
 
+const unauthenticated403ErrorCodes = new Set(['user_banned', 'user_deactivated']);
+
 /**
  * Checks if the provided error indicates the user's session is no longer valid
  * and should trigger the unauthenticated flow (e.g. sign-out / redirect to sign-in).
@@ -53,6 +55,7 @@ export function is429Error(e: any): boolean {
  * Only matches explicit authentication failure status codes:
  * - 401: session is invalid or expired
  * - 422: invalid session state (e.g. missing_expired_token)
+ * - 403: terminal user state (e.g. user_banned, user_deactivated)
  *
  * 404 is intentionally excluded despite being returned for "session not found",
  * because it's also returned for unrelated resources (org not found, JWT template
@@ -64,7 +67,10 @@ export function is429Error(e: any): boolean {
  */
 export function isUnauthenticatedError(e: any): boolean {
   const status = e?.status;
-  return status === 401 || status === 422;
+  const hasTerminalUserErrorCode =
+    Array.isArray(e?.errors) && e.errors.some((error: any) => unauthenticated403ErrorCodes.has(error?.code));
+
+  return status === 401 || status === 422 || (status === 403 && hasTerminalUserErrorCode);
 }
 
 /**