How can I turn on external sharing on SharePoint Online?
When using SharePoint it is easy to share documents and collaborate internally, but, how do you share documents externally. When using SharePoint online you are able to share content with people outside of your organization by making some small changes in your permissions.
You can control which sites can be shared externally and have reports based on usage by guests. Options for external sharing can be view, download, or share rights.
Step 1: You can add a specific guest to your SharePoint online environment.
Step 2: You can manage permissions by sharing invitations to external users or limit sharing to only members of a specified security group.
Step 3: You can manage who can send sharing invitations to external users by limiting such sharing to members of a specified security group. You can set the default type of link – and the permissions for that link – that shows when users select Get a link to share documents and folders.
Step 4: You have the option of limiting sharing for users that are outside of your organization.
For more info on external sharing check out this Microsoft blog.