check before: 2025-10-01
Product:
eDiscovery, Microsoft 365 admin center, Purview, Purview Communication Compliance, Purview compliance portal, Purview Data Loss Prevention, Teams
Platform:
Online, World tenant
Status:
Change type:
Admin impact, New feature, Updated message, User impact
Links:
Details:
Summary:
Microsoft Teams is updating private channels by increasing limits to 1000 channels per team and 5000 members per channel, enabling meeting scheduling, and shifting compliance policies from user mailboxes to team group mailboxes. Migration runs from October 2025 to January 2026; admins must update compliance policies before then.
Details:
Updated December 8, 2025: We have updated the timeline. Thank you for your patience.
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.
Private channels are no longer limited to 30 per team. Instead, private channels can be added up to the limit of 1000 total channels per team.
Private channels can now have up to 5000 members, instead of 250.
Meetings can now be scheduled in private channels.
Compliance policies for private channels are part of the team's group policies instead of the individual user level.
The migration of private channels to the updated capabilities will begin in early October 2025 and continue through January 2026 (previously December 2025). During this period, private channels will continue to operate normally. Admins and compliance managers should complete any required policy changes by October 2025 (previosly September), before the migration begins. Changes to private channel limits and meeting scheduling will follow in February 2026. Migration can start or end at different times for each tenant during the rollout period. To track progress, a new PowerShell command will be available for tenants to check whether their migration has started or is completed. This post will be updated soon with details on the PowerShell command.
[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 January 2026 (previously mid-December 2025). Updated channel limits and meeting scheduling will begin rollout in early February 2026 and we expect to complete by end of February 2026.
[Action required by compliance managers and admins]
Purview eDiscovery and Legal Hold
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.
Purview Data Loss Prevention (DLP)
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.
Purview Retention Policy
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:
In Microsoft Purview compliance portal, go to Settings, -> Optical character recognition (OCR), -> Select locations and scope to [1] all users and groups or [2] specific users and groups
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
How can admins identify a user's private channel memberships?
Use Teams Admin Center under team settings, or run PowerShell: Get-TeamChannelUser to list members.
When is compliance manager action required?
If a policy (legal hold, eDiscovery, retention, DLP) applied to a user's mailbox, in order to include private channel messages, differs from the team policies for the team hosting the private channel. Policies must be applied to the team's group 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.
During eDiscovery for users on hold or during migration, search both user mailbox and group mailbox for complete data on a private channel.
What if no action is taken?
User-level policies will not apply to a private channel's new message data. Team-level policies will apply to private channels.
Why isn't Microsoft automatically applying policies from user mailboxes to a private channel's team?
Tenant admins and compliance managers must assess and apply policies as needed. Group policies apply to all channels in the Team. Some user mailbox policies are intended for all of a user's messages, and some are intended for private channel messages. Each organization must review and decide on policies.
Is there any impact to end users?
During migration, users may see duplicate search results in Teams searches-both links will navigate to the same content in Microsoft Teams.
6. When will migration happen for my tenant and how long will it take?
Migration can start or end at different times for each tenant during the rollout period and can take some weeks depending of the tenant. To track progress, a new PowerShell command will be available for tenants to check whether their migration has started or is completed. The command will be -
Get-TenantPrivateChannelMigrationStatus -TenantId <tenantId>
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.
Change Category:
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Scope:
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Release Phase:
Created:
2025-08-14
updated:
2025-12-20
Task Type
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Docu to Check
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MS Preperations
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MS Urgency
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MS workload name
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summary for non-techies**
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Direct effects for Operations**
Compliance Policy Management
If compliance policies are not updated before migration, new private channel messages will not be governed by the correct policies, leading to potential data governance issues.
- roles: Compliance Manager, IT Administrator
- references: https://techcommunity.microsoft.com/blog/microsoftteamsblog/unlocking-the-full-potential-of-private-channels-in-microsoft-teams/4438767
Data Loss Prevention (DLP)
Failure to modify DLP policies before migration may result in new private channel messages not being protected under the appropriate DLP policies, increasing the risk of data leaks.
- roles: Compliance Manager, IT Administrator
- references: https://techcommunity.microsoft.com/blog/microsoftteamsblog/unlocking-the-full-potential-of-private-channels-in-microsoft-teams/4438767
User Experience during Migration
Users may experience duplicate search results in Teams, leading to confusion and inefficiency when trying to access private channel content.
- roles: End User, Team Member
- references: https://techcommunity.microsoft.com/blog/microsoftteamsblog/unlocking-the-full-potential-of-private-channels-in-microsoft-teams/4438767
Retention Policy Management
If retention policies are not aligned with the new group policies, there may be inconsistencies in data retention, potentially leading to data loss or non-compliance.
- roles: Compliance Manager, IT Administrator
- references: https://techcommunity.microsoft.com/blog/microsoftteamsblog/unlocking-the-full-potential-of-private-channels-in-microsoft-teams/4438767
Legal Hold Management
Without proper application of legal holds to the new group mailbox, organizations may fail to preserve critical data, risking legal repercussions.
- roles: Compliance Manager, Legal Advisor
- references: https://techcommunity.microsoft.com/blog/microsoftteamsblog/unlocking-the-full-potential-of-private-channels-in-microsoft-teams/4438767
Configutation Options**
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Opportunities**
Enhanced Compliance Management
The transition of compliance policies from individual user mailboxes to team group mailboxes will streamline compliance management, allowing compliance managers to apply policies at the group level. This reduces the administrative burden of managing individual policies for each user and ensures consistent application across private channels.
- next-steps: Conduct a review of existing compliance policies to ensure they are updated and applied to the team group mailbox before the migration starts in October 2025.
- roles: Compliance Managers, IT Administrators
- references: https://techcommunity.microsoft.com/blog/microsoftteamsblog/unlocking-the-full-potential-of-private-channels-in-microsoft-teams/4438767
Scalability of Private Channels
With the increase in limits to 1000 private channels per team and 5000 members per channel, teams can expand their collaboration efforts significantly. This will allow departments to create more focused groups for specific projects or initiatives without the need for creating multiple teams, thereby improving communication and project management.
- next-steps: Identify departments that would benefit from increased private channel limits and facilitate training sessions on effective channel management to optimize usage.
- roles: Project Managers, Team Leaders
- references: https://techcommunity.microsoft.com/blog/microsoftteamsblog/unlocking-the-full-potential-of-private-channels-in-microsoft-teams/4438767
Improved Data Loss Prevention (DLP) Policies
The shift to group-based DLP policies for private channels will enhance data security by ensuring that all private channel messages are covered under a single policy. This reduces the risk of data breaches that could occur from inconsistent policy application across individual user mailboxes.
- next-steps: Review and update DLP policies to include the team's group mailbox, ensuring that all new private channel messages are governed under the same policy framework before the migration.
- roles: IT Security Officers, Compliance Managers
- references: https://techcommunity.microsoft.com/blog/microsoftteamsblog/unlocking-the-full-potential-of-private-channels-in-microsoft-teams/4438767
Potentional Risks**
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Data Protection**
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IT Security**
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Hypothetical Work Council Statement**
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DPIA Draft**
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explanation for non-techies**
Microsoft Teams is making some changes to how private channels work, and here's a simple way to understand it. Imagine your team is like a big office building. Each private channel is like a separate room where only certain people can enter. Previously, these rooms were small, and you could only have a few people in each. Now, Microsoft is expanding these rooms, allowing up to 1000 channels per team and 5000 members per channel. It's like renovating the building to have more rooms and accommodate more people.
Another change is how messages and data are stored. Previously, each person's mailbox was like their personal filing cabinet where all their messages were kept. Now, the messages from these private rooms will be stored in a central filing cabinet for the whole team. This makes it easier to manage and find information because everything is in one place.
For those who manage compliance, this means you need to update your policies. It's like updating the rules for what can be stored in the new central filing cabinet. You need to make sure the rules apply to the whole team, not just individual filing cabinets. If you don't update the rules, new messages might not be stored correctly.
During the transition, everything will keep working as usual, but it's important to prepare before the changes start in October 2025. Think of it like getting ready for a big office move; you want to make sure everything is packed and labeled correctly so nothing gets lost.
Admins and compliance managers will have some tools to help track the progress of these changes, like a special command to check if the migration has started or finished. It's like having a checklist to ensure everything is on track during the move.
In summary, these changes are about making private channels more flexible and easier to manage, with everything stored in one place for the whole team. Just like in an office renovation, planning and preparation are key to a smooth transition.
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change history
| Date | Property | old | new |
| 2025-12-20 | MC Messages | Updated December 8, 2025: We have updated the timeline. Thank you for your patience.
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. Private channels are no longer limited to 30 per team. Instead, private channels can be added up to the limit of 1000 total channels per team. Private channels can now have up to 5000 members, instead of 250. Meetings can now be scheduled in private channels. Compliance policies for private channels are part of the team's group policies instead of the individual user level. The migration of private channels to the updated capabilities will begin in early October 2025 and continue through January 2026 (previously December 2025). During this period, private channels will continue to operate normally. Admins and compliance managers should complete any required policy changes by October 2025 (previosly September), before the migration begins. Changes to private channel limits and meeting scheduling will follow in February 2026. Migration can start or end at different times for each tenant during the rollout period. To track progress, a new PowerShell command will be available for tenants to check whether their migration has started or is completed. This post will be updated soon with details on the PowerShell command. [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 January 2026 (previously mid-December 2025). Updated channel limits and meeting scheduling will begin rollout in early February 2026 and we expect to complete by end of February 2026. Message exceeds character limit for the request portal. Adding html below for reference: https://microsoft-my.sharepoint-df.com/:t:/p/brimcg/ERmYzK2UOKBBi9726qR52nEBGw-0sPPCEc1PfogoBOxb-A?e=mfTqqs | Updated December 8, 2025: We have updated the timeline. Thank you for your patience.
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. Private channels are no longer limited to 30 per team. Instead, private channels can be added up to the limit of 1000 total channels per team. Private channels can now have up to 5000 members, instead of 250. Meetings can now be scheduled in private channels. Compliance policies for private channels are part of the team's group policies instead of the individual user level. The migration of private channels to the updated capabilities will begin in early October 2025 and continue through January 2026 (previously December 2025). During this period, private channels will continue to operate normally. Admins and compliance managers should complete any required policy changes by October 2025 (previosly September), before the migration begins. Changes to private channel limits and meeting scheduling will follow in February 2026. Migration can start or end at different times for each tenant during the rollout period. To track progress, a new PowerShell command will be available for tenants to check whether their migration has started or is completed. This post will be updated soon with details on the PowerShell command. [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 January 2026 (previously mid-December 2025). Updated channel limits and meeting scheduling will begin rollout in early February 2026 and we expect to complete by end of February 2026. [Action required by compliance managers and admins] Purview eDiscovery and Legal Hold 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. Purview Data Loss Prevention (DLP) 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. Purview Retention Policy 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: In Microsoft Purview compliance portal, go to Settings, -> Optical character recognition (OCR), -> Select locations and scope to [1] all users and groups or [2] specific users and groups 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 How can admins identify a user's private channel memberships? Use Teams Admin Center under team settings, or run PowerShell: Get-TeamChannelUser to list members. When is compliance manager action required? If a policy (legal hold, eDiscovery, retention, DLP) applied to a user's mailbox, in order to include private channel messages, differs from the team policies for the team hosting the private channel. Policies must be applied to the team's group 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. During eDiscovery for users on hold or during migration, search both user mailbox and group mailbox for complete data on a private channel. What if no action is taken? User-level policies will not apply to a private channel's new message data. Team-level policies will apply to private channels. Why isn't Microsoft automatically applying policies from user mailboxes to a private channel's team? Tenant admins and compliance managers must assess and apply policies as needed. Group policies apply to all channels in the Team. Some user mailbox policies are intended for all of a user's messages, and some are intended for private channel messages. Each organization must review and decide on policies. Is there any impact to end users? During migration, users may see duplicate search results in Teams searches-both links will navigate to the same content in Microsoft Teams. 6. When will migration happen for my tenant and how long will it take? Migration can start or end at different times for each tenant during the rollout period and can take some weeks depending of the tenant. To track progress, a new PowerShell command will be available for tenants to check whether their migration has started or is completed. The command will be - Get-TenantPrivateChannelMigrationStatus -TenantId <tenantId> 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. |
| 2025-12-20 | MC Last Updated | 12/08/2025 18:35:49 | 2025-12-20T00:59:04Z |
| 2025-12-20 | MC prepare | https://microsoft-my.sharepoint-df.com/:t:/p/brimcg/ERmYzK2UOKBBi9726qR52nEBGw-0sPPCEc1PfogoBOxb-A?e=mfTqqs | https://techcommunity.microsoft.com/blog/microsoftteamsblog/unlocking-the-full-potential-of-private-channels-in-microsoft-teams/4438767 |
| 2025-12-20 | MC Summary | Microsoft Teams private channels will transition to use a channel mailbox, increasing limits to 1000 channels per team and 5000 members per channel, with meetings allowed. Compliance policies will shift to team group level. Migration starts October 2025, completing by January 2026; new features roll out February 2026. | Microsoft Teams is updating private channels by increasing limits to 1000 channels per team and 5000 members per channel, enabling meeting scheduling, and shifting compliance policies from user mailboxes to team group mailboxes. Migration runs from October 2025 to January 2026; admins must update compliance policies before then. |
| 2025-12-09 | MC prepare | https://techcommunity.microsoft.com/blog/microsoftteamsblog/unlocking-the-full-potential-of-private-channels-in-microsoft-teams/4438767 | https://microsoft-my.sharepoint-df.com/:t:/p/brimcg/ERmYzK2UOKBBi9726qR52nEBGw-0sPPCEc1PfogoBOxb-A?e=mfTqqs |
| 2025-12-09 | MC MessageTagNames | New feature, User impact, Admin impact | Updated message, New feature, User impact, Admin impact |
| 2025-12-09 | MC Summary | Microsoft Teams private channels will transition to using a channel mailbox, increasing limits to 1000 channels per team and 5000 members per channel, with meetings supported. Compliance policies will shift from user mailboxes to the team’s group mailbox. Migration starts October 2025; admins must update policies by September 20, 2025. | Microsoft Teams private channels will transition to use a channel mailbox, increasing limits to 1000 channels per team and 5000 members per channel, with meetings allowed. Compliance policies will shift to team group level. Migration starts October 2025, completing by January 2026; new features roll out February 2026. |
| 2025-12-09 | MC Last Updated | 09/19/2025 00:50:38 | 2025-12-08T18:35:49Z |
| 2025-12-09 | MC Messages | Updated September 18, 2025: We have updated the timing and content below with additional information. Thank you for your patience.
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. Private channels are no longer limited to 30 per team. Instead, private channels can be added up to the limit of 1000 total channels per team. Private channels can now have up to 5000 members, instead of 250. Meetings can now be scheduled in private channels. Compliance policies for private channels are part of the team's group policies instead of the individual user level. The migration of private channels to the updated capabilities will begin in early October 2025 and continue through December 2025. During this period, private channels will continue to operate normally. Admins and compliance managers should complete any required policy changes by September 20, 2025, before the migration begins. Migration can start or end at different times for each tenant during the rollout period. To track progress, a new PowerShell command will be available for tenants to check whether their migration has started or is completed. This post will be updated soon with details on the PowerShell command. [When this will happen:] General Availability (Worldwide): We will begin rolling out early October 2025 (prevously late September) and expect to complete by mid-December 2025. [Action required by compliance managers and admins] Purview eDiscovery and Legal Hold 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. Purview Data Loss Prevention (DLP) 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. Purview Retention Policy 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. Microsoft policies for Optical Character Recognition Optical character recognition (OCR) is managed via Data Loss Prevention (DLP) policy. Before migration, modify the corresponding DLP policy that needs be applied for OCR to private channels and change locations to all users and groups. Frequently asked questions How can admins identify a user's private channel memberships? Use Teams Admin Center under team settings, or run PowerShell: Get-TeamChannelUser to list members. When is compliance manager action required? If a policy (legal hold, eDiscovery, retention, DLP) applied to a user's mailbox, in order to include private channel messages, differs from the team policies for the team hosting the private channel. Policies must be applied to the team's group 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. During eDiscovery for users on hold or during migration, search both user mailbox and group mailbox for complete data on a private channel. What if no action is taken? User-level policies will not apply to a private channel's new message data. Team-level policies will apply to private channels. Why isn't Microsoft automatically applying policies from user mailboxes to a private channel's team? Tenant admins and compliance managers must assess and apply policies as needed. Group policies apply to all channels in the Team. Some user mailbox policies are intended for all of a user's messages, and some are intended for private channel messages. Each organization must review and decide on policies. Is there any impact to end users? During migration, users may see duplicate search results in Teams searches-both links will navigate to the same content in Microsoft Teams. When will migration happen for my tenant and how long will it take? Migration can start or end at different times for each tenant during the rollout period and can take some weeks depending of the tenant. To track progress, a new PowerShell command will be available for tenants to check whether their migration has started or is completed. The command will be: Get-TenantPrivateChannelMigrationStatus -TenantId 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. | Updated December 8, 2025: We have updated the timeline. Thank you for your patience.
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. Private channels are no longer limited to 30 per team. Instead, private channels can be added up to the limit of 1000 total channels per team. Private channels can now have up to 5000 members, instead of 250. Meetings can now be scheduled in private channels. Compliance policies for private channels are part of the team's group policies instead of the individual user level. The migration of private channels to the updated capabilities will begin in early October 2025 and continue through January 2026 (previously December 2025). During this period, private channels will continue to operate normally. Admins and compliance managers should complete any required policy changes by October 2025 (previosly September), before the migration begins. Changes to private channel limits and meeting scheduling will follow in February 2026. Migration can start or end at different times for each tenant during the rollout period. To track progress, a new PowerShell command will be available for tenants to check whether their migration has started or is completed. This post will be updated soon with details on the PowerShell command. [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 January 2026 (previously mid-December 2025). Updated channel limits and meeting scheduling will begin rollout in early February 2026 and we expect to complete by end of February 2026. Message exceeds character limit for the request portal. Adding html below for reference: https://microsoft-my.sharepoint-df.com/:t:/p/brimcg/ERmYzK2UOKBBi9726qR52nEBGw-0sPPCEc1PfogoBOxb-A?e=mfTqqs |
| 2025-12-09 | MC Title | Microsoft Teams: Private channels increased limits and transition to group compliance | (Updated) Microsoft Teams: Private channels increased limits and transition to group compliance |
| 2025-12-09 | MC End Time | 02/09/2026 09:00:00 | 2026-03-30T10:00:00Z |
| 2025-09-19 | MC Messages | 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. Private channels are no longer limited to 30 per team. Instead, private channels can be added up to the limit of 1000 total channels per team. Private channels can now have up to 5000 members, instead of 250. Meetings can now be scheduled in private channels. Compliance policies for private channels are part of the team's group policies instead of the individual user level. The migration of private channels to the updated capabilities will begin in late September 2025 and continue through December 2025. During this period, private channels will continue to operate normally. Admins and compliance managers should complete any required policy changes by September 20, 2025, before the migration begins. Migration can start or end at different times for each tenant during the rollout period. To track progress, a new PowerShell command will be available for tenants to check whether their migration has started or is completed. This post will be updated soon with details on the PowerShell command. [When this will happen:] General Availability (Worldwide): We will begin rolling out late September 2025 and expect to complete by mid-December 2025. [Action required by compliance managers and admins] Purview eDiscovery and Legal Hold 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. Purview Data Loss Prevention (DLP) 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. Purview Retention Policy 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. Frequently asked questions How can admins identify a user's private channel memberships? Use Teams Admin Center under team settings, or run PowerShell: Get-TeamChannelUser to list members. When is compliance manager action required? If a policy (legal hold, eDiscovery, retention, DLP) applied to a user's mailbox, in order to include private channel messages, differs from the team policies for the team hosting the private channel. Policies must be applied to the team's group 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. During eDiscovery for users on hold or during migration, search both user mailbox and group mailbox for complete data on a private channel. What if no action is taken? User-level policies will not apply to a private channel's new message data. Team-level policies will apply to private channels. Why isn't Microsoft automatically applying policies from user mailboxes to a private channel's team? Tenant admins and compliance managers must assess and apply policies as needed. Group policies apply to all channels in the Team. Some user mailbox policies are intended for all of a user's messages, and some are intended for private channel messages. Each organization must review and decide on policies. Is there any impact to end users? During migration, users may see duplicate search results in Teams searches-both links will navigate to the same content in Microsoft Teams. 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. | Updated September 18, 2025: We have updated the timing and content below with additional information. Thank you for your patience.
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. Private channels are no longer limited to 30 per team. Instead, private channels can be added up to the limit of 1000 total channels per team. Private channels can now have up to 5000 members, instead of 250. Meetings can now be scheduled in private channels. Compliance policies for private channels are part of the team's group policies instead of the individual user level. The migration of private channels to the updated capabilities will begin in early October 2025 and continue through December 2025. During this period, private channels will continue to operate normally. Admins and compliance managers should complete any required policy changes by September 20, 2025, before the migration begins. Migration can start or end at different times for each tenant during the rollout period. To track progress, a new PowerShell command will be available for tenants to check whether their migration has started or is completed. This post will be updated soon with details on the PowerShell command. [When this will happen:] General Availability (Worldwide): We will begin rolling out early October 2025 (prevously late September) and expect to complete by mid-December 2025. [Action required by compliance managers and admins] Purview eDiscovery and Legal Hold 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. Purview Data Loss Prevention (DLP) 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. Purview Retention Policy 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. Microsoft policies for Optical Character Recognition Optical character recognition (OCR) is managed via Data Loss Prevention (DLP) policy. Before migration, modify the corresponding DLP policy that needs be applied for OCR to private channels and change locations to all users and groups. Frequently asked questions How can admins identify a user's private channel memberships? Use Teams Admin Center under team settings, or run PowerShell: Get-TeamChannelUser to list members. When is compliance manager action required? If a policy (legal hold, eDiscovery, retention, DLP) applied to a user's mailbox, in order to include private channel messages, differs from the team policies for the team hosting the private channel. Policies must be applied to the team's group 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. During eDiscovery for users on hold or during migration, search both user mailbox and group mailbox for complete data on a private channel. What if no action is taken? User-level policies will not apply to a private channel's new message data. Team-level policies will apply to private channels. Why isn't Microsoft automatically applying policies from user mailboxes to a private channel's team? Tenant admins and compliance managers must assess and apply policies as needed. Group policies apply to all channels in the Team. Some user mailbox policies are intended for all of a user's messages, and some are intended for private channel messages. Each organization must review and decide on policies. Is there any impact to end users? During migration, users may see duplicate search results in Teams searches-both links will navigate to the same content in Microsoft Teams. When will migration happen for my tenant and how long will it take? Migration can start or end at different times for each tenant during the rollout period and can take some weeks depending of the tenant. To track progress, a new PowerShell command will be available for tenants to check whether their migration has started or is completed. The command will be: Get-TenantPrivateChannelMigrationStatus -TenantId 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. |
| 2025-09-19 | MC Last Updated | 08/14/2025 01:10:45 | 2025-09-19T00:50:38Z |
| 2025-09-19 | MC Summary | Microsoft Teams is enhancing private channels by increasing limits to 1000 channels per team and 5000 members per channel, enabling meetings, and shifting compliance policies from user mailboxes to team group mailboxes. Migration starts late September 2025; admins must update policies by September 20, 2025. | Microsoft Teams private channels will transition to using a channel mailbox, increasing limits to 1000 channels per team and 5000 members per channel, with meetings supported. Compliance policies will shift from user mailboxes to the team’s group mailbox. Migration starts October 2025; admins must update policies by September 20, 2025. |
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