External Sharing in Microsoft 365: What Small Businesses Should Review

External sharing is useful, but it can quietly become risky if nobody reviews it. Microsoft 365 makes it easy to share files through OneDrive, SharePoint, and Teams. That convenience helps small businesses work with clients, vendors, accountants, contractors, and remote staff. The problem is that shared links and guest access can outlive the project they were created for.

A practical external sharing review is not about shutting collaboration down. It is about knowing what is shared, who can access it, and whether that access still makes sense.

Start With Where Files Are Shared

Files may be shared from OneDrive, SharePoint document libraries, Teams channels, private channels, or shared folders. The first step is understanding where business documents actually live. If staff are sharing from personal OneDrive folders when the files belong to a team, that can create confusion later.

Team documents usually belong in SharePoint or Teams-connected libraries, not in one employee’s personal storage.

Review Anonymous And Anyone Links

Anonymous links, often called “anyone with the link” access, are convenient but higher risk. If the link is forwarded, anyone who receives it may be able to view or edit the file depending on settings. Some businesses disable these links entirely. Others allow them only for low-risk content.

• Are anonymous links allowed?
• Do links expire automatically?
• Can external users edit files or only view them?
• Are sensitive folders excluded from open sharing?

Check Guest Users

Guest users can be useful for longer-term collaboration, but they should be reviewed. Former vendors, old project partners, and inactive contractors may still have access if nobody removes them. Guest access should have an owner inside the business.

Separate Client Collaboration From Internal Work

Do not mix internal working files with client-facing shared folders unless the permissions are clearly managed. A dedicated client folder or project site can reduce the chance that internal notes, financial information, or unrelated files are shared by accident.

Use Expiration And Review Habits

External sharing should not be “set and forget.” Use link expiration where possible, review shared files after projects end, and include guest access cleanup in offboarding or vendor change processes. A simple quarterly review can prevent a lot of stale access.

What To Review During Cleanup

During cleanup, look for files shared with personal email addresses, guests who have not accessed files recently, links with edit permission, and sharing on folders that contain mixed sensitive and non-sensitive content. Also check whether staff understand the difference between sharing a file and giving someone access to an entire folder or site.

For sensitive client, finance, HR, or legal files, sharing should be more controlled. That may mean named guests only, view-only access, expiration dates, or moving files into a more appropriate SharePoint site.

A Practical Next Step

If your team uses Microsoft 365 heavily, review anonymous links, guest users, and externally shared SharePoint/OneDrive content. OnlineV can help with Microsoft 365 support and practical sharing cleanup for Calgary and remote teams.