Microsoft Teams is one of the most used online communication and collaboration tools out there, which makes sense given how well it integrates with other Microsoft products and how frequently it receives new features. Now, Microsoft has announced a major upcoming change to the infrastructure of private channels in Teams.
As the name implies, private channels enables more directed and focused conversations between dedicated workstreams and teams. It allows confidential files to be stored in private repositories in the channel while giving channel owners the ability to govern access to the discussions and other content hosted in a channel.
Since the use of private channels is growing, Microsoft is introducing an infrastructure change to simplify compliance. Soon, private channels will use a group mailbox like shared channels rather than individual mailboxes. This will result in the maximum private channels per team to jump from 30 to 1,000, and maximum members per channel to increase from 250 to 5,000. Additionally, meeting scheduling will be supported following this change, and compliance will be applicable at a group level rather than individuals.
Microsoft has shared some initial guidance regarding the preparations that IT admins can make for this change. They need to ensure that compliance policies are applied at a team"s group scope prior to the infrastructure migration. While policies on individual mailboxes will still be applicable, new private channel data will be managed by the policies configured on the group mailbox. IT admins can refer to additional guidance here regarding the configuration changes that they should account for in Microsoft Purview.
Microsoft has emphasized that this change will greatly benefit customers who have been requesting more flexibility and simplified compliance for private channels in Teams. The infrastructure migration process is set to begin in late September 2025 and wrap up before 2026 begins. During this time, mailboxes will be gradually rolled over, but will continue to be accessible, so there should be no downtime.