External sharing gives SharePoint and OneDrive users a way to share content with people outside the organization. Microsoft sets it on by default for the entire environment. Organization settings come first and sites can only be stricter. Anonymous Anyone links exist next to guest sign in. Microsoft suggests switching sharing off globally until you plan its use.
Vendors, clients and partners need documents from your SharePoint sites. External sharing delivers them without copying files into email. Wrong settings expose confidential content. Plan the setup first.
Facts follow the Microsoft Learn page Overview of external sharing in SharePoint and OneDrive in Microsoft 365. Older posts call the platform SharePoint Online in Office 365. Microsoft now documents it under Microsoft 365.
What is External Sharing?
Microsoft defines external sharing as sharing SharePoint and OneDrive content with people outside your organization like partners, vendors, clients or customers. It also includes sharing between licensed users on several Microsoft 365 subscriptions.
Microsoft states that external sharing is on by default for the entire SharePoint and OneDrive environment. Microsoft suggests switching it off globally before users start using sites or until you know how you want to use it.
How do Organization and Site Settings Work Together?
- Organization first. External sharing must be allowed at the organization level before any site can allow it.
- Sites can be stricter. Sites can restrict sharing further. When site and organization settings differ the most restrictive value applies.
- OneDrive. OneDrive settings can match or restrict SharePoint settings and never exceed them.
- New sites. Not every new site permits external sharing even when the organization setting does.
How are External Guests Authenticated?
Microsoft describes two models. SharePoint external authentication handles files and folders and creates no guest account when Microsoft Entra B2B integration is off. Sites always use Entra B2B. With the integration enabled a guest account always exists and Entra settings apply.
| Sharing target | Integration off | Integration on |
|---|---|---|
| Files and folders | No guest account created | Guest account always created |
| Sites | Entra B2B always used | Guest account always created |
What About Anyone Links?
Microsoft calls these anonymous links. Stop sharing through an Anyone link by deleting the link on the file or folder or by switching off Anyone links for the site. Even when Anyone links are allowed users can still share with guests who sign in and with internal users.
How to Reduce the Risk?
- Put confidential content in sites with external sharing off.
- Limit internal sharing by preventing site members from sharing and by enabling access requests.
- Add guests to a Microsoft 365 group only when they need the site. Removing the group permission can break Teams features.
- Reshare invitations that you sent through the legacy Invitation Manager. Microsoft states that those invitations stopped granting access in June 2024.
Guests in a shared folder see one another in the Manage Access panel. Unlicensed guests can view and edit in Office.com. They cannot install desktop Office without a license.
What does Microsoft Not Say?
Microsoft never names the four sharing options in the SharePoint admin center and does not say where to configure them. It also gives no license requirements. Older posts describe site collection steps from the Office 365 era. Microsoft pages used here do not confirm those steps.
Related reading: SharePoint Online migration checklist and how to enable multifactor authentication in Office 365.
Frequently Asked Questions
What does External Sharing Mean?
It means sharing SharePoint and OneDrive content with people outside your organization. Microsoft sets it on by default.
Which Setting Wins When Site and Organization Differ?
Most restrictive value wins.
How do You Stop an Anyone Link?
Delete the link on the file or folder or switch off Anyone links for the site.
Do Guests Get an Account?
Not always. SharePoint external authentication creates no guest account for files and folders. Entra integration always creates one.
Can OneDrive Allow More Sharing Than SharePoint?
No. OneDrive settings can match or restrict SharePoint settings.
Key Takeaways
- External sharing is on by default in SharePoint and OneDrive.
- Organization settings come first and sites can only be stricter.
- Differing settings resolve to the most restrictive value.
- Anyone links stop when you delete the link or switch the option off.
- Confidential content belongs in sites with external sharing off.
Sources and References
Facts follow Microsoft Learn.