This is a question that has been asked by several of my clients, so I thought I’d address it here. When you’re using Teams or Skype for Business with Microsoft as a telephony provider, whether with an international or domestic calling plan, the outbound call appears as your Office 365 domain name or city. For example, when I make an outbound call, it looks like the call is coming from Caragol.com or sometimes Chicago, IL depending on how the lookup is performed.
This is your CNAM or Caller-ID Name. To be clear, caller ID refers to your phone number, while CNAM is the name associated with the caller ID.
The question is, can you change it? The answer is yes but not via PowerShell or the Admin Console. If you need to change it, you’ll need to send an email to PTN@Microsoft.com, the number porting team. You’ll want to send your text string of no more than 15 characters to them. If you have multiple, you can send them in XLS format with the number in one column and the new CNAM in the other.
Hopefully this helps you out if you find yourself in this situation.