SMS API Error 135: "You cannot have access to another user" with Admin-Managed App

[russmcbride (Russell)]

I’m building a Zapier integration using Zoom’s SMS API (POST /phone/sms/messages) and encountering Error 135 when trying to send SMS on behalf of other users in our organization.

Current Setup

• App Type: Admin-managed

• Scopes: user:read:admin and phone:read:sms_message

• Authorization: Done by Zoom account admin

• API Endpoint: https://api.zoom.us/v2/phone/sms/messages

What Works

• Sending SMS from the authenticated admin user’s phone number works perfectly

• API authentication is successful

• Basic SMS functionality is working

What Doesn’t Work

• Sending SMS on behalf of other users in the same Zoom account returns Error 135

• Using other users’ phone_user_id in the sender object fails

Request Body Structure

json

{
  "message": "Test message",
  "to_members": [
    {
      "phone_number": "+1234567890"
    }
  ],
  "sender": {
    "user_id": "8umOrlLzSZmghxw6_lnYvw"  // This is the phone_user_id from /phone/users
  }
}

Key Details

1. User ID Format: I’m using the phone_user_id from the /phone/users endpoint, not the regular Zoom user_id

2. Same Account: The target user is in the same Zoom account as the admin who authorized the app

3. Phone License: The target user has an active Zoom Phone license and assigned phone number

4. Permissions: The app has admin-level scopes and was authorized by an account admin

Questions

1. Are additional scopes required for cross-user SMS sending beyond phone:read:sms_message?

2. Is there a specific permission or setting in the Zoom Admin Console that needs to be enabled?

3. Should I be using a different user ID format for the sender object?

4. Are there account-level restrictions that prevent admin apps from sending SMS on behalf of other users?

Error Response

json

{
  "code": 135,
  "message": "You cannot have access to another user."
}

Any guidance on the correct configuration for cross-user SMS functionality would be greatly appreciated!

Environment

• Integration: Third-party (Zapier)

• App Category: Admin-managed OAuth app

• Account Type: Business/Enterprise with Zoom Phone

[elisa.zoom (Elisa)]

hi @russmcbride
Thanks for reaching out to us.
This is expected behavior. As of right now, SMS’s can’t be sent on behalf of other users.

[omar.delgado (Omar)]

I had this issue and I create the new app using the user I wanted to send the SMS.