MC1528011 - Microsoft Teams: External presenter support for event group chat

Microsoft 365 Message Center announcement MC1528011.

MS Message Center's Summary

Microsoft Teams is introducing external presenter support for event group chat in meetings using the green room option, with rollout scheduled from November to December 2026. Administrators must verify that external user collaboration is enabled to allow external participants to read and post messages during events.

Administrator impact
Verify external user collaboration settings in the Teams admin centre if your organisation plans to use this feature.
End user impact
External presenters will be able to participate in private event group chats during meetings that have the green room enabled.
Importance
4/10: This is a feature update that introduces new cross tenant communication capabilities requiring specific external collaboration settings.

Microsoft Summary

Microsoft Teams will support external presenters in event group chat for meetings with the "Enable Green room" option. Rollout starts November 2026. External collaboration must be enabled. External presenters can read and post messages, with tenant IDs updated accordingly, enabling cross-tenant communication.

Message Center ID
MC1528011
Category
stay Informed
Severity
normal
Services
Microsoft Teams
Tags
New feature, Feature update, User impact, Admin impact
Roadmap ID
573706
Platforms
Android, Desktop, iOS, Mac
Published
2026-10-27
Last updated
2026-10-27
Expires
2027-01-08

[What and why] We are adding support for external presenters in event group chat, the private chat used by organizers, co-organizers, and presenters for coordination during an event or structured meeting. This change enables presenters who are outside the tenant hosting the meeting or event to participate in the event group chat. [Rollout schedule] General Availability (Worldwide): Rollout will begin in early November 2026 and is expected to complete by early December 2026. [Impact on your organization] Who is affected Organizers, co-organizers, and presenters using event group chat in meetings or events, including external presenters. Platforms and services Microsoft Teams Event group chat Meetings and events with the Enable Green room Teams meeting option enabled What will happen External presenters will be able to join the event group chat used for coordination during a meeting or event. The meeting or event must have the Enable Green room Teams meeting option enabled to use event group chat. External user collaboration must be enabled for external presenters to use this functionality. [Action required and recommendations] If your organization wants external presenters to use event group chat, ensure external user collaboration is enabled in Teams admin center > External collaboration . [Compliance considerations] Does the change store new customer data? No. Expected changes on the client will only correct the tenantId to the external federated presenter's own tenant. Does the change alter how existing customer data is processed, stored, or accessed (e.g., documents, emails, chats, etc.)? Yes. External federated presenters can now read and post in the event group chat. That includes messages written before they joined, if the thread shows history. The presenter's stored tenantId also changes from the organizer's tenant to the presenter's own tenant. Does the change provide a new way of communicating between users, tenants, or subscriptions? Yes. We are adding a new cross-tenant chat path between the organizer's tenant and external presenters. Both tenants must allow external access. Does the change modify how users can access, export, delete, or correct their personal data within Microsoft 365 services (GDPR Data Subject Rights)? No. External presenters' messages fall under existing federated-chat handling.