What are the best ways to monitor and audit permissions across a SharePoint environment in Microsoft 365. There isn’t one single “magic button,” but rather a combination of tools and practices that form the most effective approach.

The “best” way depends on your specific needs (scale, complexity, budget, compliance requirements), but generally involves a multi-layered strategy:

1. Leveraging Built-in Microsoft 365 Tools:

• Microsoft Purview Compliance Portal (Audit Log):

  • What it does: Records actions related to permissions and sharing. This includes granting access, changing permissions, creating sharing links, accepting/revoking sharing invitations, adding/removing users from groups, etc.
    

  • Pros: Centralized logging across M365 services (not just SharePoint). Captures who did what, when. Essential for forensic auditing and tracking changes over time. Can set up alerts for specific activities.
    

  • Cons: Reports events, not the current state of permissions easily. Can generate a large volume of data, requiring effective filtering and analysis. Default retention might be limited (90 days for E3, 1 year for E5/add-ons, up to 10 years with specific licenses). Doesn’t give you a simple snapshot of “who has access to Site X right now“.
    

  • Best for: Auditing changes to permissions, investigating specific incidents, monitoring for policy violations (e.g., excessive external sharing).

• SharePoint Site Permissions & Advanced Permissions:

  • What it does: The standard SharePoint interface (Site Settings > Site Permissions and Advanced permission settings) allows site owners and administrators to view current permissions on a specific site, list, or library. The “Check Permissions” feature is useful for specific users/groups.
    

  • Pros: Direct view of current permissions for a specific location. No extra tools needed. Good for spot checks by site owners or admins.
    

  • Cons: Entirely manual, site-by-site. Not feasible for auditing across the entire tenant. Doesn’t scale. Doesn’t show how permissions were granted (direct vs. group) easily in aggregate. Doesn’t provide historical data.

• Site Usage Reports (Sharing Links):

  • What it does: Found under Site Settings > Site Usage, this includes reports on externally shared files and sharing links (Anyone, Specific People).
    

  • Pros: Quick overview of sharing activity for a specific site, particularly external sharing links.
    

  • Cons: Limited scope (focuses on sharing links, not inherited or direct permissions). Site-by-site basis.

• PowerShell (SharePoint Online Management Shell / PnP PowerShell):

  • What it does: Allows administrators to scriptmatically query and report on permissions across multiple sites, lists, libraries, and even items (though item-level reporting can be slow). PnP PowerShell is often preferred for its richer feature set.
    

  • Pros: Highly flexible and powerful. Can automate the generation of comprehensive current state permission reports across the tenant. Can export data to CSV for analysis. Can identify broken inheritance, unique permissions, group memberships, etc. Free (part of M365).
    

  • Cons: Requires scripting knowledge. Can be slow to run across very large environments, especially if checking item-level permissions. Scripts need to be developed and maintained. Requires appropriate administrative privileges.
    

  • Best for: Periodic, deep audits of the current permission state across the environment. Generating custom reports. Automating permission inventory.

• Azure AD Access Reviews (Requires Azure AD Premium P2):

  • What it does: Automates the review process where group owners or designated reviewers must attest to whether users still need access via Microsoft 365 Groups or Security Groups that grant access to SharePoint sites (often via the Owners, Members, Visitors groups).
    

  • Pros: Proactive governance. Engages business users/owners in the review process. Reduces permission creep over time. Creates an audit trail of reviews.
    

  • Cons: Requires Azure AD P2 license. Primarily focuses on group memberships, not direct permissions or SharePoint groups (though M365 groups are the modern standard). Requires setup and configuration.
    

  • Best for: Implementing regular, automated reviews of group-based access to ensure continued need.

2. Third-Party Tools:

• What they do: Numerous vendors offer specialized SharePoint/Microsoft 365 administration, governance, and auditing tools (e.g., ShareGate, AvePoint, Quest, SysKit, CoreView, etc.).
  

• Pros: Often provide user-friendly dashboards and pre-built reports for permissions auditing. Can simplify complex reporting tasks compared to PowerShell. May offer advanced features like alerting, automated remediation workflows, comparison reporting (permissions changes over time), and broader M365 governance capabilities. Can often combine state reporting and change auditing.
  

• Cons: Cost (licensing fees). Can have their own learning curve. Reliance on a vendor for updates and support. Need to grant the tool potentially high privileges.
  

• Best for: Organizations needing comprehensive, user-friendly reporting and management without extensive PowerShell expertise, or those requiring advanced features and workflows not available natively. Often essential for large, complex environments or those with stringent compliance needs.

Recommended Strategy (The “Best Way”):

For most organizations, the most effective approach is a combination:

1. Configure & Monitor the Purview Audit Log: Ensure auditing is enabled and understand how to search/filter logs. Set up alerts for critical permission changes or sharing events (e.g., creation of “Anyone” links if disallowed, granting owner permissions). This covers ongoing change monitoring.
   

2. Perform Regular Audits using PowerShell or a Third-Party Tool: Schedule periodic (e.g., quarterly, semi-annually) comprehensive audits to capture the current state of permissions across all relevant sites. Focus on:
   
   • Sites with broken inheritance.
     

   • Direct user permissions (should be minimized).
     

   • Membership of Owners groups.
     

   • External sharing status.
     

   • Usage of SharePoint Groups vs M365/Security Groups.
3. Implement Azure AD Access Reviews (if licensed): Use this for regular recertification of access granted via M365 and Security groups, especially for sensitive sites.
   

4. Establish Clear Governance Policies: Define who can share, what can be shared externally, how permissions should be managed (use groups!), and the responsibilities of Site Owners.
   

5. Train Site Owners: Ensure they understand the principle of least privilege and how to manage permissions correctly within their sites using M365 groups primarily.
   

6. Use Built-in UI for Spot Checks: Empower admins and site owners to use the standard SharePoint UI for quick checks on individual sites as needed.

By combining proactive monitoring (Purview), periodic deep audits (PowerShell/Third-Party), automated reviews (Access Reviews), and clear governance, you create a robust system for managing and auditing SharePoint permissions effectively.