MC1528011: Microsoft Teams Adds External Presenter Support to Event Group Chat

📢 Official Microsoft Message Center Announcement

[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.

Source: Microsoft Message Center • Analysed by MWPro