Updated March 30,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 early mid-May 2026 (previously early April)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.