My business Caller ID name appearing incorrectly on T-Mobile phones

I just did this as well. It was a little frustrating but here is what I did step by step.

1. Called ATT customer support 1800TMOBILE
2. Explicitly said I am not a customer but I am having issues with my business caller ID not showing correctly on ATT Customer Phones. (Took a few times of repeating this for them to get it right)
3. Asked to be escalated to the Technicians
4. After a lot of back and forth and holding, the Tech found out what I needed (after explaining it to them) and she was able to help. I asked her what I needed to do next time I needed to call in. She gave me these instructions:
   A. Tell the technician to go to their “Grandcentral” system.
   B. Click “Tools”
   C. Search Tools and type “Number Details Tool”
   D. When the number details tool opens, there is a place to type the phone number that you need the CID updated for (your phone number).
   E. Right away there is a place to type the requested Caller ID Name.
   F. Click Submit and it will report the number details and your request will take 72 hours to update.

The tech I worked with said she had never heard of this before but learned something new. She said to do the above every time we needed a CID number update.
This worked for us.

Some other resources:
T-Mobile Caller ID report NOT spam (if your number is mistakenly being reported as spam - https://callreporting.t-mobile.com/

First Orion Caller ID registry (Database that TMobile is supposed to pull from but doesn’t - https://portal.firstorion.com/app/landing/#/signup

We had already done both of these things and the CID sitll wasn’t updated for months, but after the call and 72 hours, it was fixed.