Masking Incoming Caller Numbers in Microsoft Teams

Occasional Contributor

Hello everyone - 


So we are in the Government Community Cloud (GCC) for O365 and would like to set up our tenant to mask the phone numbers for incoming callers in our meetings to protect privacy. I have seen that it can be set up to clock all of the numbers except for the last few digits. I have dug around and I dont see the clear cut method for doing that. I see how to mask our OUTGOING calls from our Teams environment but not incoming. Can you point us in the right direction?

7 Replies

@4BobRandall hi there- I believe the feature you are requesting is actually rolling out right now and can be managed with policies- "As an admin, you can use caller ID policies in Microsoft Teams to change or block the caller ID (also known as calling line ID). By default, the phone number of Teams users can be seen when they make a call to a PSTN phone and the phone number of PSTN callers can be seen when they call a Teams user. You can use caller ID policies to display an alternate phone number for Teams users in your organization or block an incoming number from being displayed."


Please note - Don't see this feature in the Microsoft Teams admin center yet? It's currently being rolled out and might not be available in your organization yet. 
Here is more info:

I hope this was helpful :)


@Ethan Stern I see that as masking outgoing calls from Teams to PSTN. I am talking about masking the phone number for people who dial into Teams meetings so the other attendees dont see their whole phone number. They would only see the last three or so digits in the number. I have seen it work in other tenants. 

@4BobRandall hi there - here is more info, you can block incoming caller ID - 

  • Change their outgoing caller ID You can replace a user's Caller ID, which by default is their telephone number, with another phone number. For example, you could change the user's Caller ID from their phone number to a main phone number for your business or change the user's Calling Line ID from their phone number to a main phone number for the legal department. You can change the Calling ID number to any Online service number (toll or toll-free).


    If you want to use the Service parameter, you must specify a valid service number.

  • Block their outbound caller ID You can block the outgoing Caller ID from being sent on a user's outgoing PSTN calls. Doing this will block their phone number from being displayed on the phone of a person being called.

  • Block their incoming caller ID You can block a user from receiving Caller ID on any incoming PSTN calls.

@Ethan Stern and are you asking for Online PSTN connectivity?  Or thinking of users dialing in to meetings another way?

@4BobRandall some more info on the masking number from outside your org feature:


best response confirmed by 4BobRandall (Occasional Contributor)

@4BobRandall ok, Bob - last reply, LOL! 


Looks like this might be exactly what you need - rollout was pushed:

I was thinking you were trying to set it up in your PSTN online - check your admin message center in your tenant for more info: MC220415


"Microsoft Teams: Enable tenant administrators to configure masking of PSTN participant phone numbers

For customers with Audio Conferencing enabled for their Teams meetings, we are providing the ability for tenant administrators to define how Audio Conferencing participants' phone numbers appear in the roster view for meetings scheduled within their organization: masked to external users, masked for everyone, or off (visible to everyone)."

Nailed it Eathan ... thats the upcoming change. I thought it was already out there in GCC but I guess it isnt. Not I just need to find the details on how to enable it once it appears in our tenant. Thanks a lot!