The Caller ID policy on Microsoft Teams enables a user assigned to a specific Caller ID policy to display their CLI to be either their phone number or private. Service numbers that are purchased directly from Microsoft Teams is not supported at this time on the @voice platform. 

To have this feature setup:

On Microsoft Teams Admin Panel

From the left navigation pane, select Voice and then click on Caller ID policies. Add a new policy by selecting Add. Give the policy a name and a description. Make sure you turn on Override the caller ID policy and for Replace the caller ID with, you will need to select User's number.

After saving the caller ID policy. The user will now be able to control what CLI is displayed when making a call, either their DID number or as a Private Call.

The user can toggle this settings from the Microsoft Teams app by clicking on Settings and selecting Calls. Scrolling down, under the Caller ID section, check Hide my phone number and profile information for all calls to set calls to be Private Calls or uncheck it to display the users DID number as the CLI.