Review the update and plan any required actions before rollout.
Primary Audience
Why this score?
AT A GLANCE
END USERS
IT ADMINS
ROLLOUT TIMELINE
Late October 2026
📢 Official Microsoft Message Center Announcement
(Updated) Microsoft Teams: Improved file sharing experience in external chats
Message ID: MC1479514 (Updated)
Updated October 1, 2026: We have updated the content. Thank you for your patience.
[What and why]
We’re improving the file-sharing experience in Microsoft Teams external (federated) chats by making the Attach file (paperclip) and drag-and-drop experiences available by default. This change only impacts tenants who have not adjusted the policy that controls file attachment in an external Teams chat. To opt out of this change, disable the capability using the Teams PowerShell setting provided in the “Action required and recommendations” section below. This can be done before the rollout and your policy setting will be respected. This update does not change your OneDrive or SharePoint external-sharing settings or override existing access restrictions.
Prior to this change, when existing OneDrive and SharePoint policies allow, users can already share files in external chats by sharing a link to the file. This update makes that flow easier by adding the Attach file (paperclip) and drag-and-drop experiences directly in Teams. Files uploaded from the user’s device are stored in the sender’s OneDrive, while cloud files remain stored in their existing location. Teams then assigns permissions to chat participants, subject to existing OneDrive and SharePoint sharing policies. Senders can still review, modify, or remove file access before sending the message. This reduces the need to assign permissions manually, while allowing senders to stay in control.
[Rollout schedule]
- Targeted Release: Beginning in late October 2026 and expected to complete by late November 2026
- General Availability (Worldwide, GCC, GCC High, DoD): Beginning in late October 2026 and expected to complete by late November 2026
[Impact on your organization]
Who is affected
- Organizations using Microsoft Teams external access (federation)
- This change applies only to organizations where the setting has not been explicitly configured. Any customers who have left the configuration in the default state will be impacted.
- Users participating in external 1:1 chats, external group chats, and meeting chats
Platforms and services
- Microsoft Teams
- External (federated) 1:1 chats
- External (federated) group chats
- Meeting chats
- Teams desktop app
- Teams web app
What will happen
- The ability for users to attach and share files in external chats will be enabled for all Microsoft 365 tenants, unless your organization has previously explicitly disabled this setting in Teams. Any customers who have left the configuration in the default state will be impacted.
- Users can already paste file links into external chants. This ability is unchanged. With this change, users will also have the ability to attach and share files using the paperclip option or drag and drop in external (federated) chats.
- Files shared through these experiences continue to be stored and shared through OneDrive or SharePoint. Files uploaded from a user’s device are stored in the sender’s OneDrive, while existing cloud files remain in their current location.
- Organizations that want the Teams attachment experience in external chats to remain disabled must reapply the disabled setting after rollout.
- When automatic permission assignment is enabled, Teams assigns permissions to participants in the external chat for files uploaded using paperclip or drag-and-drop, subject to existing OneDrive and SharePoint policies.
- Senders can review, modify, or remove sharing permissions before sending a file.
- Senders can continue to modify or revoke access after a file has been shared.
- Automatic permission assignment applies only to files shared through the paperclip or drag-and-drop experience.
- The files will be shared as hyperlinks after send.
- Existing OneDrive and SharePoint sharing controls continue to govern access.
- Existing sensitivity labels, domain restrictions, and security protections continue to apply.
[Action required and recommendations]
No action is required to preserve external-sharing restrictions already configured in OneDrive and SharePoint; this update does not change those restrictions. To review or change these controls, see Manage sharing settings for SharePoint and OneDrive in Microsoft 365.
[To disable file attachments in external chats]
To opt out of this change, apply the following Teams PowerShell setting if you have not already explicitly configured this setting:
Set-CsTeamsFilesPolicy -Identity Global -FileSharingInChatsWithExternalUsers Disabled
Verify the setting:
Get-CsTeamsFilesPolicy | Select Identity, FileSharingInChatsWithExternalUsers
Recommended actions:
- Review your SharePoint, OneDrive, and Microsoft Entra external sharing configuration because these settings continue to govern what external recipients can access.
- Inform helpdesk and support teams about the updated attachment experience and the distinction between Teams attachment controls and OneDrive/SharePoint access controls.
- Update user training and internal documentation as needed.
- Communicate to users that:
- They can attach files directly in chats with people outside the organization.
- When automatic permission assignment is enabled, Teams assigns chat participants access to files shared via paperclip icon, subject to existing OneDrive and SharePoint policies. Senders can review, modify, or remove access before sending.
- Pasted file links retain their existing permissions.
- Files uploaded to external chats are stored in the sender’s OneDrive and display.
Optional configuration to allow attachments without automatic permission assignment:
To disable automatic permission assignment while continuing to allow file attachments in external chats:
Set-CsTeamsMessagingPolicy -Identity Global -AutoShareFilesInExternalChats Disabled
If automatic permission assignment is disabled, users may need to manually grant access to shared files before external recipients can open them.
Allow several hours for policy changes to propagate before users see the updated experience.
Learn more:
[Compliance considerations]
| Question | Answer |
| Does the change alter how existing customer data is processed, stored, or accessed? | Yes. Uploaded files shared through Attach or drag-and-drop can automatically receive permissions for participants in external chats. Existing OneDrive and SharePoint controls continue to govern access. Uploaded files are stored in the sender’s OneDrive. |
| Does the change provide a new way of communicating between users, tenants, or subscriptions? | Yes. The direct file-attachment experience in external (federated) chats becomes available by default; the existing ability to paste file links remains unchanged. |
| Does the change include an admin control, and can it be controlled through Entra ID group membership? | Yes. Admins can separately control Teams file attachments and automatic permission assignment through Teams PowerShell policies. OneDrive and SharePoint sharing settings continue to govern external file access. |
Source: Microsoft Message Center • Analysed by MWPro
<<< [MC1479514] Archive
Tooltip: View earlier revisions of this post
