January 26, 2026 Microsoft is preparing to add a new layer of fraud protection to Teams calls, aiming to stop scammers before conversations even begin. Starting next month, users will see on-screen warnings when an external caller appears to be impersonating a trusted brand.
The feature, called Brand Impersonation Protection, will begin rolling out to Microsoft’s targeted release customers in mid-February and will be switched on by default. It focuses on first-time VoIP calls from outside an organization, analyzing signals that suggest a caller may be posing as a legitimate business or government entity.
“Brand Impersonation Protection for Teams Calling adds proactive safeguards against fraudulent or deceptive external callers who attempt to appear as trusted organizations,” Microsoft said in a Microsoft 365 message center update. “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.”
According to the company, the system checks these incoming calls in real time and surfaces a high-risk warning before the call is answered. If the suspicious indicators continue, the alert can remain visible during the conversation. Users will still be able to accept, block or end the call, but the persistent warnings are designed to interrupt scams that rely on urgency and misplaced trust.
The company says the feature does not require any administrative setup, but it is encouraging organizations to prepare for user questions once the alerts start appearing. IT teams are advised to update internal guidance and brief helpdesk staff so they can explain why calls are being flagged and how users should respond.
The new warning system is part of efforts by Microsoft to harden Teams against abuse. Earlier this year, the company began automatically strengthening messaging protections by default, including malicious URL detection, blocking weaponizable file types and improving reporting for false positives. Another upcoming update will alert administrators to suspicious traffic coming from external domains.
With more than 320 million monthly users relying on Teams for work calls, Microsoft is betting that visible, in-the-moment warnings will help counter a growing wave of voice-based scams, especially those that exploit familiar brand names to extract money or sensitive information.
