Recent posts have surfaced experiences with spam calls to users on Teams. We wanted to share some best practices for admins and what individual users can do to prevent unwanted calls.
For admins:
Teams-to-Teams
Admins can tighten external communications policies to protect users and their org from unwanted calls. Through the unified external collab settings in the Teams Admin Center, IT admins can configure external collaboration policies for all users securely and efficiently. You can select from predefined modes for quick set up or customize settings when you need more flexibility. For more information on setting these up, click here.
Admins can also block unauthenticated or anonymous external users from joining meetings hosted by anyone in your org. To do this:
- In the left navigation of the Teams admin center, go to Meetings > Meeting settings.
- Under Participants, turn the Anonymous users can join a meeting toggle On or Off.
- Select Save.
PSTN calls
Admins can also customize block settings for incoming PSTN calls. Through PowerShell, you can define a list of number patterns and exceptions at the tenant global level so the caller ID of every incoming PSTN call to the tenant can be checked against the list for a match. If a match is made, an incoming call is rejected or routed to a resource account. For instructions on call blocking, check out: Block inbound calls in Microsoft Teams - Microsoft Teams | Microsoft Learn
Intelligent Call Delegation
We also have a new feature in public preview if your organization is enrolled in the Frontier early access program. Intelligent Call Delegation uses AI to answer calls on your behalf, engage with the caller, and provide details about who is calling and why, helping you focus on the conversations that matter most.
It's a great option for handling unknown callers, reducing interruptions, and making more informed decisions about which calls require your immediate attention. Learn more here. Stay tuned for broader availability as we continue bringing this experience to more customers.
Individual users
While robust spam protections are controlled at the admin level, individual users can also block anonymous calls. To do so:
- Click … > Settings > Privacy > Blocked contacts > Toggle on Block calls with no caller ID
Users can also report suspicious Teams calls.
- Go to call history or post call experience in Teams and select … > Report call.
- Security concern. is already selected as the reason. Enter additional explanation as required.
- Review the selections and select Report.
We hope this helps! What controls or policies have made the biggest difference in shutting down spam calling at your org?
If you’ve run into a technical problem with Teams, submit it in Feedback -> Report a Bug. It’s the direct line to our engineering team.