| MC1134737 | (Updated) Microsoft Teams: Private channels increased limits and transition to group compliance |
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| Classification | planForChange |
|---|---|
| Last Updated | 04/08/2026 16:22:05 |
| Start Time | 08/13/2025 23:09:57 |
| End Time | 06/01/2026 08:00:00 |
| Message Content |
Updated April 8, 2026: The migration of private channels continues with most migration now complete (95%). Organizations can check status including % complete in their tenants with the PowerShell cmdlet listed below. Migration is scheduled to complete by late April 2026, with some special cases that will require additional time: private channels with an empty membership list or guest-only membership are rare cases and will require additional steps, and this post will be updated with more details on those special cases. New limits for private channels will rollout starting late April 2026. Private channels not yet migrated would not receive new limits until their migration is complete. In response to customer feedback, we are introducing enhanced flexibility, greater scalability, and streamlined compliance management for private channels in Microsoft Teams. Note: It is important for compliance managers to review and take appropriate action before migration starts for these changes to private channels. [What’s changing?] Private channels will transition use a channel mailbox instead of individual user mailboxes. Organizations with compliance policies (retention, legal hold, data loss prevention, or eDiscovery) for private channels must review these policies and must apply policies to the Microsoft 365 group for the channel’s team before migration begins to ensure continuity of the policy for a private channel. Existing policies will continue to apply to user mailboxes; post-migration, new data will be governed by policies on the group. Note that policies applied to the team’s group can apply to all channels in the team. After the transition to updated private channels in your organization, private channels will be updated as follows.
The migration of private channels will begin in early October 2025 and continue through late April 2026 (previously March). During this period, private channels will continue to operate normally. Admins and compliance managers should complete any required policy changes by October 2025, before the migration begins. Changes to private channel limits and meeting scheduling will follow in late April through early May 2026 (previously early April). As part of this change, newly created private channels will not be created with a document library by default; the root folder is used as a default location for any new files.
[When this will happen:] General Availability (Worldwide): We will begin rolling out private channel migration early October 2025 (previously late September) and expect to complete by late April 2026 (previously March). Updated channel limits and meeting scheduling will complete in early May 2026 (previously April). Restricted clouds rollout will begin in April 2026 (previously March). [Action required by compliance managers and admins]
With this change, private channel data will move from user mailboxes to the group mailbox, aligning with how shared channels data is stored. Previously, legal holds were applied to user mailboxes since private channel data resided in each member’s mailbox. Post-migration, the latest version of private channel message data from each user’s mailbox is moved to the private channel’s group mailbox. Message edits and deleted messages will not be copied into the group mailbox. Note: For users on hold, copies of message edits and deleted messages will remain in the user’s preserved library folder until the hold expires, while the latest version of private channel message data from each user’s mailbox is copied to the private channel’s group mailbox. Before migration If a legal hold exists for a private channel, admins must also apply the policy to the team’s group, in addition to the policy already applied to users’ mailboxes, in order for a hold to apply to new data generated and stored in the private channel’s mailbox. Note that policies applied to the team’s group can apply to all channels in the team. Screenshot 1: Setting up a new hold in Microsoft Purview compliance portal. After migration For existing holds admins will need to ensure that the hold is applied to the user mailbox as well as the new group mailbox, in order for a hold to apply to existing and new message data. Any new legal holds will need to be applied to the group. For complete eDiscovery, include both the private channel’s users’ mailboxes and the team’s group mailbox to retrieve pre-migration messages, message history, and post-migration new content. Screenshot 2: Configuring an eDiscovery search in Microsoft Purview compliance portal.
With this change, private channel messages will be included as a part of the DLP policy scoped to the private channel’s team’s group, as opposed to the user mailbox. Before migration Admins must modify the “Teams chat and channel messages” policy for private channels to add the team’s group containing the private channel, in addition to the user mailbox, in order to include new private channel messages in a policy. Note that policies applied to the team’s group can apply to all channels in the team. After migration Ensure that “Teams chat and channel messages” policy for private channels is scoped to the team’s group containing the private channel. Screenshot 3: Configuring a data loss prevention policy in Microsoft Purview compliance portal.
After this change, creation of new private channel-specific policies will not be possible in the Purview portal. Instead, “Teams channel messages” policies applied to the team’s group will now include private channels. Existing private channel policies will remain in effect and preserve all held message data in user mailboxes. Editing of existing policies will not be supported but policies can be removed. Before migration Apply current private channel retention policies (previously on user mailboxes) to Teams channel messages to include the team’s group, in order to include new private channel messages in a policy. In Microsoft Purview compliance portal, go to solutions > Data Lifecycle Management > Retention policies. Note that policies applied to the team’s group can apply to all channels in the team. After migration If the parent team’s group retention policy differs from the private channel’s policy, create a new or equivalent policy to ensure consistent retention.
Screenshot 4: Configuring “Teams channel messages” for a retention policy in Microsoft Purview compliance portal.
4. Microsoft policies for Optical Character Recognition Before Migration: After Migration: Set the settings for “all users and groups” to cover private channels as specific users and groups are not supported.
Frequently asked questions
Please refer to this blog post for more information: New enhancements in Private Channels in Microsoft Teams unlock their full potential We appreciate your attention to this important update.
Please refer to this blog post for more information: New enhancements in Private Channels in Microsoft Teams unlock their full potential We appreciate your attention to this important update. |
