MC1181772 – M365 Change Digest

One-line summary

Teams now enables automatic file and Loop sharing with external chat users. Admins gain policy controls over auto-sharing, and Entra B2B Guests can share files from their home tenant.

Similar updates

Details

RoadmapIds

492625

FeatureStatusJson

{"492625":[{"RoadmapId":492625,"Platform":"Web","Status":"Launched","LastUpdateTime":"2026-03-31T03:00:23.9755025Z","LatestRing":"StandardRelease"},{"RoadmapId":492625,"Platform":"Mac","Status":"Scheduled","LastUpdateTime":"2026-03-31T03:00:23.9755026Z","LatestRing":null},{"RoadmapId":492625,"Platform":"Desktop","Status":"Scheduled","LastUpdateTime":"2026-03-31T03:00:23.9755027Z","LatestRing":null},{"RoadmapId":492625,"Platform":"All","Status":"InRollout","LastUpdateTime":"2026-03-31T03:00:23.9755028Z","LatestRing":"StandardRelease"}]}

Summary

Microsoft Teams will enable automatic file and Loop component sharing in external 1:1, group, and meeting chats, improving collaboration. Guests can share files from their own OneDrive or SharePoint. IT admins can disable automatic sharing via policy. Rollout starts late October 2025, and completed late March 2026.

Platforms

Desktop, Mac, Web

Body (from Message Center)

Updated March 30, 2026: We have updated the title. Thank you for your patience.

[Introduction]

We’re improving external collaboration in Microsoft Teams by enabling file attachments and Loop sharing in 1:1, group and meeting chats with external users. This update improves the collaboration experience for Files and Loop and add a new control for IT admins. Specifically, Files and Loop components will be shared automatically with external participants in the chat and won’t require any action by the sender by default. Additionally, Entra B2B Guests in your organization will be able to attach and share files from their home tenant’s OneDrive or SharePoint.

This change applies to Teams for Windows desktop, Mac desktop, and web and is associated with Roadmap ID 492625.

Screenshot 1: File sharing option is available in external chats

user settings

Screenshot 2: Files shared have an external label and always open on Web

user settings

Screenshot 3: Teams automatically shares the file or Loop component when uploaded to external chats

user settings

Screenshot 4: User can also manually change permissions before sharing

user settings

[When this will happen:]

Targeted Release: Rollout begins late October 2025; expected to complete by mid-November 2025
General Availability (Worldwide): Rollout begins mid-January 2026

[How this affects your organization:]

Who is affected:

All Microsoft Teams users in your organization who participate in 1:1, group, or meeting chats with external users, including guest and Teams for Free users.

What will happen:

With this update:

Unless the user chooses to share File and Loop by pasting links, external users in chat will be automatically provisioned to allow frictionless collaboration.
You can disable automatic provisioning and have the user change permissions manually by using policy controls.
If disabled, users will have to manually provision the file to users in the chat.
Guest users will be able to upload files from their home tenant’s OneDrive and SharePoint.
Files shared by external users will continue to display an External tag for clarity.
Loop components will now be rendered inside external chats in Teams.
Recipients will access File and Loop components as B2B guests within the resource tenant. If they are not already added as guests, they will need to give consent and might need to complete MFA, depending on your company’s B2B policy, before viewing the chat content.

What you can do to prepare:

No action is required to enable the feature—it will be automatically available as the rollout progresses.
To disable the automatic provisioning behavior for files and loops set the AutoShareFilesInExternalChats attribute of TeamsMessagingPolicy to Disabled. Learn more: Set-CsTeamsMessagingPolicy documentation.
To provide seamless Loop access experience for external users, we recommend turning on Entra B2B Guest Access. Refer to: Microsoft Entra B2B integration for SharePoint & OneDrive - SharePoint in Microsoft 365 | Microsoft Learn.
For configuration guidance, refer to: Set-CsTeamsFilesPolicy documentation (documentation will be updated before rollout).
Review the following article: Share Files and Loop components in external (federated) chats

Compliance considerations

Compliance Area	Impact
New communication method between tenants	Enables file sharing in external chats, expanding cross-tenant collaboration
Admin control available	Admins can disable the feature via PowerShell
Can be controlled through Entra ID group membership	Policy can be scoped using Entra ID groups
Data processing changes	Files shared in external chats are tagged and stored per existing Teams file sharing protocols

Raw JSON (for debugging)

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    "action_required_by": null,
    "ai_action_required_by": "2026-10-31T00:00:00Z",
    "ai_actions": [
      "Review and adjust TeamsMessagingPolicy to disable auto-sharing if desired",
      "Ensure Entra B2B Guest Access is enabled for seamless Loop access",
      "Review documentation for file sharing compliance and setup"
    ],
    "ai_master_tags": [
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      "Admin"
    ],
    "ai_model": "gpt-4.1",
    "ai_summary": "Teams now enables automatic file and Loop sharing with external chat users. Admins gain policy controls over auto-sharing, and Entra B2B Guests can share files from their home tenant.",
    "ai_topics": [
      "Teams",
      "SharePoint",
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      "Entra"
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    "category": "stayInformed",
    "details_map": {
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      "Platforms": "Desktop, Mac, Web",
      "RoadmapIds": "492625",
      "Summary": "Microsoft Teams will enable automatic file and Loop component sharing in external 1:1, group, and meeting chats, improving collaboration. Guests can share files from their own OneDrive or SharePoint. IT admins can disable automatic sharing via policy. Rollout starts late October 2025, and completed late March 2026."
    },
    "id": "MC1181772",
    "importance": 0,
    "is_major_change": false,
    "last_modified": "2026-03-30T16:21:41Z",
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    "platforms": "Desktop, Mac, Web",
    "roadmap_ids": [
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    "services": [
      "Microsoft Teams"
    ],
    "severity": "normal",
    "tags": [
      "Updated message",
      "Feature update",
      "Admin impact"
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    "title": "(Updated) Microsoft Teams: Secure file and Loop sharing in external 1:1, group and meeting chats"
  }
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