While organization-wide sharing controls are set on the Sharing page in the SharePoint Admin center, you can also further restrict sharing controls on individual SharePoint sites. Follow these steps to manage the external sharing capabilities at the site level:
- Navigate to the SharePoint Admin center. Go to https://admin.microsoft.com, expand Admin Centers, and select SharePoint.
- From the navigation menu, select Sites | Active Sites to display the list of sites.
- Select a site and scroll down in the flyout to the External sharing section, as highlighted in the following screenshot, and click the Edit link:
- On the Sharing flyout, select the appropriate level of sharing. You can only select a level of sharing as permissive as the organization's setting. Click Save when you're finished.
If you are working through governance activities for your SharePoint Online tenant, you may want to block external sharing globally until you have policies (both procedural and technical) in place to protect your organization.
Next, we'll examine some of the available security options.