Microsoft Teams now has guest access on by default

What you need to know

• Guest access is now on by default for Microsoft Teams.
• Previously, admins had to turn on guest access.
• The change started on February 8, 2021.

Guest access for Microsoft Teams is now turned on by default. Until now, guest access had to be specifically turned on by an admin before people could add guests. As of February 8, 2021, Microsoft switched guest access on by default for Teams, which lines it up with other services from Office 365.

If you prefer to keep guest access off, you can easily swap it off. You just need to go into your Org-wide settings and toggle guest access off.

The switch is pretty straightforward, but Microsoft breaks it down in a Tech Community post:

• Until February 2021, guest access is still turned off by default. You must turn on guest access for Teams before admins or team owners can add guests. After you turn on guest access, it might take a few hours for the changes to take effect. If users see the message Contact your administrator when they try to add a guest to their team, it's likely that either guest access hasn't been turned on or the settings aren't effective yet.
• After February 2021, guest access in Microsoft Teams will be turned on by default for new customers & existing customers who haven't configured this setting. When this change is implemented, if you've not already configured guest access capability in Microsoft Teams, that capability will be enabled in your tenant. If you want guest access to remain disabled for your organization, you'll need to confirm that the guest access setting is set to Off instead of Service default.

The Tech Community post also answers some frequently asked questions, including clarifying that nothing will change if you already have guest access enabled.