API - Assign a phone number to a user - Wrong Outbound Caller ID set

API Endpoint(s) and/or Zoom API Event(s)
POST /phone/users/{userId}/phone_numbers
POST /phone/users/{userId}/outbound_caller_id/customized_numbers

Description
*We are currently facing the same problem as found on the dev forum:
Link to forum question: "Assign a phone number to a user" Call & Outbound Caller ID *

We were advised to use this API to resolve our issue: Add phone numbers for users’ customized outbound caller ID

We are using both Okta and ServiceNow to add phone numbers to users. The primary numbers are synchronised from Okta and all further numbers directly from ServiceNow via REST.

I have tried with my own user to change the outbound caller id (back) to my primary number but without success. I get a http 201 for the API request, but in my profile (see screenshot) the outbound caller id and the available numbers stay the same.

Error?
No error

How To Reproduce
Initial situation: Zoom Phone Pro users with one primary phone number
Steps to reproduce the behavior:
1. User orders a second phone number
2. Phone number is added to user
3. Outbound caller id is set to newly added number

Expected behavior
When an additional phone number is added to a user, then the outbound caller id should stay

Hi @dennis.barth
Thanks for reaching out to us!
I am not able to see the screenshot that you are referring to.
Could you please share the entire request URL that you are sending along with the request body for that request that you are getting a 201 code so I can look into it

Hi @elisa.zoom

Here are the details. I have to check, how I can add the screenshot (does not allow media content).

Whenever I added another phone number via API, my outbound caller id was updated. With the payload above I could not define customized outbound caller id: +41 31 330 30 01 (primary)

Hi @dennis.barth
Sorry for the late reply here.
I think I was able to replicate this on my end.
So when I tried to call the endpoint
POST /phone/users/{userId}/phone_numbers, I kept getting errors, was not able to add phone numbers due to a validation error

But then I tried the second endpoint you are using
POST /phone/users/{userId}/outbound_caller_id/customized_numbers, and I got a 201 Ok status, but then I tried to query the endpoint
GET /phone/users/{userId}/outbound_caller_id/customized_numbers and my response is empty, so no changes were added.

I will go ahead and send you a private message so you can share with me more details and I will create an internal ticket for this matter.
Thanks,
Elisa