Transferring calls to MS Teams client

Copper Contributor



We are developing a 3-rd party application that involves VoIP Calling, and we want to integrate with Teams.

With MS Graph API, we were able to query for Teams users and display them in UI.

What we want is to provide the ability to transfer the ongoing call, from outside Teams boundaries, to selected Teams user.


Could you please help us find answers to the following questions:

  1. What are the "per tenant" requirements to enable calls transferring from outside Teams boundaries to Teams Client / Teams user?
  2. Does each tenant have their own SIP Trunk number or it has to be configured by tenant administrator?
  3. If there is no SIP Trunk to place calls, what methods MS Teams provide to perform voice & calls interactions from outside Teams boundaries?


Thanks in advance!

6 Replies
Could you please share where exactly is the service outside of Teams?

Hi @HunaidHanfee-MSFT, Thanks for quick reply!


The service is contact center, that uses Avaya Aura SBC for PSTN calls.





@vtyagunov -
Thanks for the update, We are confirming this internally.
I will get back to you soon.


best response confirmed by vtyagunov (Copper Contributor)

Please have a look at this doc-
Let us know if you have any query.


Hunaid Hanfee


If the response is helpful, please click "**Mark as Best Response**" and like it. You can share your feedback via Microsoft Teams Developer Feedback link. Click here to escalate.

Any updates on this?


Hi @HunaidHanfee-MSFT !

That page was really helpful.
Thank you for help!