O365 groups make up the sun in the O365 solar system. And every Microsoft Teams team (planet?) must have an O365 group to exist. You’ll also use O365 groups for group email and calendars, defining permissions for private Stream channels, collaborating with group members in Planner, and much more.
When you create a new team from scratch, it automatically creates an O365 group (and a SharePoint site collection). Whomever you invite to that team is added to the O365 group which is also used to define permissions in other apps and services throughout O365.
But let’s say you were using O365 groups before Teams was cool. You don’t want to create duplicate teams or have to manage twice as many, right? Luckily, you can use existing O365 groups to create new teams.
Create a team using an existing O365 group
In Teams, beneath your list of Teams, click Join or create a team.
Click Create team.
Choose Create from…
Next, click Office 365 group.
If you choose Team, it will copy that Team’s apps, settings, and channels to the new Team (without changing the original Team). This might be useful for classes with similar formats, or creating committees or teams based on a well-received template.
But to create a team from our existing O365 group, we’re going to select Office 365 group.
Now select the existing O365 group for which you’re establishing a new Team, then click Create.
After a moment, your new Team will be created and you’ll be taken to its landing page.
You can verify membership is correct by opening the Team’s menu (ellipses) and selecting Manage team. This
Here you can view owners, members, and guests from the O365 group. You can now modify the O365 group’s membership here if you wish, keeping in mind it affects permissions outside of Teams as well (as is the nature of O365 groups).
Microsoft recommends modifying O365 group permissions via Teams because doing so elsewhere (such as the M365 admin center) will cause a delay in taking effect and removed team members may retain Teams chat access for a couple hours.