You have a Teams Phone deployment that contains a branch office.

Calling policies in Teams

In Microsoft Teams, calling policies control which calling and call forwarding features are available to users. Calling policies determine whether a user can make private calls, use call forwarding or simultaneous ringing to other users or external phone numbers, route calls to voicemail, send calls to call groups, use delegation for inbound and outbound calls, and so on.

You can use the global (Org-wide default) policy that ' s created automatically or create and assign custom policies.

Calling policies include:

* Prevent toll bypass and send calls through the PSTN

Turning on this setting sends calls through the Public Switched Telephone Network (PSTN) and incur charges rather than sending them through the network and bypassing the tolls. This setting is off by default.