diff --git a/packages/ramps-controller/CHANGELOG.md b/packages/ramps-controller/CHANGELOG.md
index 57f07c4838..6edd622bd0 100644
--- a/packages/ramps-controller/CHANGELOG.md
+++ b/packages/ramps-controller/CHANGELOG.md
@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- Export `getTransakApiMessage` and `isTransakPhoneRegisteredError` for consumers handling `TransakApiError`, and centralize known Transak API error codes in `transakErrorCodes.ts` ([#9135](https://github.com/MetaMask/core/pull/9135))
+
 ### Changed
 
 - Bump `@metamask/profile-sync-controller` from `^28.1.1` to `^28.2.0` ([#9119](https://github.com/MetaMask/core/pull/9119))
diff --git a/packages/ramps-controller/src/TransakService.ts b/packages/ramps-controller/src/TransakService.ts
index a88e5b6c70..515cfb5581 100644
--- a/packages/ramps-controller/src/TransakService.ts
+++ b/packages/ramps-controller/src/TransakService.ts
@@ -5,6 +5,7 @@ import type {
 import { createServicePolicy, HttpError } from '@metamask/controller-utils';
 import type { Messenger } from '@metamask/messenger';
 
+import { TRANSAK_ERROR_CODES } from './transakErrorCodes';
 import type { TransakServiceMethodActions } from './TransakService-method-action-types';
 
 // === TYPES ===
@@ -429,8 +430,6 @@ function getPaymentWidgetBaseUrl(environment: TransakEnvironment): string {
 
 // === TRANSAK API ERROR ===
 
-const TRANSAK_ORDER_EXISTS_CODE = '4005';
-
 export class TransakApiError extends HttpError {
   readonly errorCode: string | undefined;
 
@@ -915,7 +914,7 @@ export class TransakService {
       if (
         error instanceof TransakApiError &&
         error.httpStatus === 409 &&
-        error.errorCode === TRANSAK_ORDER_EXISTS_CODE
+        error.errorCode === TRANSAK_ERROR_CODES.ORDER_EXISTS
       ) {
         await this.cancelAllActiveOrders();
         await new Promise((resolve) =>
diff --git a/packages/ramps-controller/src/index.ts b/packages/ramps-controller/src/index.ts
index 7cc2d69e2a..84ab48769e 100644
--- a/packages/ramps-controller/src/index.ts
+++ b/packages/ramps-controller/src/index.ts
@@ -173,6 +173,10 @@ export {
   TransakEnvironment,
   TransakOrderIdTransformer,
 } from './TransakService';
+export {
+  getTransakApiMessage,
+  isTransakPhoneRegisteredError,
+} from './transakApiErrorUtils';
 export type {
   TransakServiceMethodActions,
   TransakServiceSendUserOtpAction,
diff --git a/packages/ramps-controller/src/transakApiErrorUtils.test.ts b/packages/ramps-controller/src/transakApiErrorUtils.test.ts
new file mode 100644
index 0000000000..418b88ea0a
--- /dev/null
+++ b/packages/ramps-controller/src/transakApiErrorUtils.test.ts
@@ -0,0 +1,27 @@
+import {
+  getTransakApiMessage,
+  isTransakPhoneRegisteredError,
+} from './transakApiErrorUtils';
+import { TRANSAK_ERROR_CODES } from './transakErrorCodes';
+import { TransakApiError } from './TransakService';
+
+describe('transakApiErrorUtils', () => {
+  const phoneRegisteredError = new TransakApiError(
+    400,
+    "Fetching 'https://api.transak.com/user' failed with status '400'",
+    TRANSAK_ERROR_CODES.PHONE_ALREADY_REGISTERED,
+    'Phone registered with t***@test.com',
+  );
+
+  it('reads apiMessage from TransakApiError', () => {
+    expect(getTransakApiMessage(phoneRegisteredError)).toBe(
+      'Phone registered with t***@test.com',
+    );
+    expect(getTransakApiMessage(new Error('generic'))).toBeUndefined();
+  });
+
+  it('detects phone already registered errors', () => {
+    expect(isTransakPhoneRegisteredError(phoneRegisteredError)).toBe(true);
+    expect(isTransakPhoneRegisteredError(new Error('generic'))).toBe(false);
+  });
+});
diff --git a/packages/ramps-controller/src/transakApiErrorUtils.ts b/packages/ramps-controller/src/transakApiErrorUtils.ts
new file mode 100644
index 0000000000..dad971fc1e
--- /dev/null
+++ b/packages/ramps-controller/src/transakApiErrorUtils.ts
@@ -0,0 +1,13 @@
+import { TRANSAK_ERROR_CODES } from './transakErrorCodes';
+import { TransakApiError } from './TransakService';
+
+export function getTransakApiMessage(error: unknown): string | undefined {
+  return error instanceof TransakApiError ? error.apiMessage : undefined;
+}
+
+export function isTransakPhoneRegisteredError(error: unknown): boolean {
+  return (
+    error instanceof TransakApiError &&
+    error.errorCode === TRANSAK_ERROR_CODES.PHONE_ALREADY_REGISTERED
+  );
+}
diff --git a/packages/ramps-controller/src/transakErrorCodes.ts b/packages/ramps-controller/src/transakErrorCodes.ts
new file mode 100644
index 0000000000..5b8b6d1436
--- /dev/null
+++ b/packages/ramps-controller/src/transakErrorCodes.ts
@@ -0,0 +1,13 @@
+/**
+ * Known Transak API error codes surfaced by {@link TransakApiError}.
+ *
+ * Values are normalized to strings because TransakService stringifies numeric
+ * codes when parsing API responses.
+ */
+export const TRANSAK_ERROR_CODES = {
+  ORDER_EXISTS: '4005',
+  PHONE_ALREADY_REGISTERED: '2020',
+} as const;
+
+export type TransakErrorCode =
+  (typeof TRANSAK_ERROR_CODES)[keyof typeof TRANSAK_ERROR_CODES];