[Introduction]

To improve file reliability and alignment with common customer workflows, Microsoft Teams is updating the default file open preference for Word, Excel, and PowerPoint files. Users who previously selected Teams as their default file opening option will now default to Desktop app or Web app instead. This change reflects customer feedback and ongoing improvements to file performance and consistency across Microsoft 365.

[When this will happen]

General Availability (Worldwide, GCC, GCC High, DoD): We will begin rolling out in early May 2026 and expect to complete by mid-May 2026.

[How this affects your organization]

Who is affected

Users in Microsoft 365 tenants who previously set Teams as their default app for opening Word, Excel, or PowerPoint files.

What will happen

• The default file open preference will change from Teams to Desktop app or Web app.
• This change applies automatically; no admin configuration is required.
• Users can manually change their file open preference back to Teams at any time from their Teams settings.
• There is no change to file storage location or permissions.

First run experience dialog shown to users when the updated default file open preference takes effect:

[What you can do to prepare]

• No admin action is required.
• Consider notifying helpdesk staff and end users about the change to reduce support requests.
• Optional internal message you can reuse:
  • “If you notice Office files opening in Desktop or Web instead of Teams, this is an expected update. You can change your preference anytime in Teams settings.”

[Compliance considerations]