A Microsoft 365 group is a membership service in Active directory that allows you to connect multiple Microsoft 365 teamwork services.
Because the group provides access to other services like Teams and SharePoint, it is important to know how that access is granted when you plan a migration or decide to connect a SharePoint site to a Microsoft 365 Group.
To learn more about the interactions between a group and other services, see The relationship between Microsoft 365 Groups, Microsoft Teams, and other services.
Index
Membership and permissions
In this example, we will look at a Microsoft 365 group with a connected team and SharePoint site.
Membership between the team and the group
Your owners and members are shared between the group and team. If you add an owner in one or the other, it is added for both.
Membership between the group and the SharePoint site
The membership of your group is automatically applied to the associated SharePoint site. For example, if you add an owner to the group or team, that owner is automatically part of the SharePoint owners group.
Additionally, owners of the group become site collection admins of the associated SharePoint site.
Adding new users to these groups in your SharePoint site however, does not add them to the Microsoft 365 group or team.
For more information, see the Microsoft article Site permissions after Microsoft 365 group connection.
How your Microsoft 365 group membership affects your migrations
When you migrate a site to a Microsoft 365 group connected site with the Azure the ShareGate migration tool app consented, the user account you use for the migration, the owners, and the site collection admins of your source site are added to the owners of the destination group. The members of your SharePoint site are added to the members of your destination group.
For more information see the Default behaviors section of Copy structure and content - Microsoft 365 Groups.
Note: When you migrate a site object or item with custom permissions to a site connected to a Microsoft 365 Group, it becomes accessible to all of the associated group and team owners since they are also site collection admin.