(Updated) Brand impersonation protection for Teams Calling

Updated May 5, 2026: We have updated the timeline. Thank you for your patience. 

[Introduction]

Brand Impersonation Protection for Teams Calling adds proactive safeguards against fraudulent or deceptive external callers who attempt to appear as trusted organizations. This helps reduce social-engineering risks and improves tenant security when users receive first-contact external calls. This update aligns with Microsoft’s ongoing investments in caller identity protection and secure collaboration.

This message is associated with Microsoft 365 Roadmap ID 543239.

[When this will happen:]

Targeted Release: Rollout will begin mid-May 2026 (previously early May) and is expected to complete by late May (previously late April).
General Availability: Timelines will be communicated in a future message.

[How this affects your organization:]

Who is affected:

• All organizations using Microsoft Teams Calling that receive inbound VoIP calls from first-contact external callers.

What will happen:

• Teams will evaluate inbound calls for signs of brand impersonation.
• Users will see high-risk call warnings before answering suspicious calls.
• Warnings may continue during the call if risk signals persist.
• Users can accept, block, or end the call.
• The feature will be enabled by default.
• Existing Teams Calling policies remain unchanged.

[What you can do to prepare:]

No admin action is required at this time.

• Inform helpdesk staff that users may begin seeing high-risk call warnings.
• Update internal training materials if applicable.
• Review Microsoft documentation on caller ID security when available.

Before rollout, we will update this post with new documentation.

[Compliance considerations:]

No compliance considerations identified, review as appropriate for your organization.