Team connected SharePoint sites default external sharing setting

Noticed a strange behavior where Team connected SharePoint sites are all defaulting to Existing guests external sharing setting. After spending some time on Internet and working with Microsoft, it is determined that this is happening because of SharePoint & OneDrive’s external sharing setting. Kind of obvious! Duh!

Here is how external sharing settings for SharePoint and OneDrive were set:

• SharePoint – New and existing guests
• OneDrive – Only people in your organization
• Other than this M365 Groups are not open for guests.

You would expect Teams connected SharePoint sites to pick up either one of these setting. Strange that it picked up and defaulted to Existing guests only.

Note: This behavior is expected and is dependent on SharePoint & OneDrive (may be other services) external sharing setting.

To test out this theory, I updated external sharing settings for OneDrive and allowed guests to be invited to Teams & M365 Groups.

Below are my new external sharing settings:

Once these settings are turned on and a new Team is created, connected SharePoint site is created with default sharing as ‘New and existing guests‘ as it should. Reference: External sharing overview Microsoft article.

It once again proves that Teams is deeply connected with SharePoint and OneDrive beyond what we see on surface.

If you notice a different sharing setting for Teams connected SharePoint sites, remember to check and adjust both SharePoint and OneDrive sharing settings because they play a part in what Teams picks up as its default.