diff --git a/.changeset/slimy-windows-grab.md b/.changeset/slimy-windows-grab.md
new file mode 100644
index 0000000000..9938f9a128
--- /dev/null
+++ b/.changeset/slimy-windows-grab.md
@@ -0,0 +1,12 @@
+---
+'@clerk/backend': patch
+---
+
+Deprecate `createSMSMessage` and `SMSMessageApi` from `clerkClient`.
+
+The `/sms_messages` Backend API endpoint will also be dropped in the future since this feature will no longer be available for new Clerk instances.
+
+For a brief period it will still be accessible for instances that have used it in the past 7
+days (13-11-2023 to 20-11-2023).
+
+New instances will get a 403 forbidden response if they try to access it.
diff --git a/packages/backend/src/api/endpoints/SMSMessageApi.ts b/packages/backend/src/api/endpoints/SMSMessageApi.ts
index a6234c7ad9..a47b9cc471 100644
--- a/packages/backend/src/api/endpoints/SMSMessageApi.ts
+++ b/packages/backend/src/api/endpoints/SMSMessageApi.ts
@@ -1,3 +1,5 @@
+import { deprecated } from '@clerk/shared/deprecated';
+
 import type { SMSMessage } from '../resources/SMSMessage';
 import { AbstractAPI } from './AbstractApi';
 
@@ -8,8 +10,18 @@ type SMSParams = {
   message: string;
 };
 
+/**
+ * @deprecated This endpoint is no longer available and the function will be removed in the next major version.
+ */
 export class SMSMessageAPI extends AbstractAPI {
+  /**
+   * @deprecated This endpoint is no longer available and the function will be removed in the next major version.
+   */
   public async createSMSMessage(params: SMSParams) {
+    deprecated(
+      'SMSMessageAPI.createSMSMessage',
+      'This endpoint is no longer available and the function will be removed in the next major version.',
+    );
     return this.request<SMSMessage>({
       method: 'POST',
       path: basePath,