SharePoint external sharing policy tiers

Overview

External sharing enables collaboration but is a common auditor focus. Layer site, tenant, and conditional access.

Tiers example

1. Blocked default for HR/legal site collections.
2. Existing guests only for standard projects.
3. New + existing guests only on isolated sites with expiration policies.

Technical controls

• Site-level external sharing settings override inherited where needed.
• Domain allow/deny lists for known partners.

User training

How to request a guest account; never forward anonymous links for regulated data.