Copilot doesn't create new access. It reveals the access you already have.
Microsoft 365 Copilot works inside your permissions. It can only show a user what that user could already open. That sounds reassuring until you remember how many files in a typical tenant are shared far more widely than anyone intended.
Before Copilot, an overshared salary spreadsheet sat in an old Teams channel where nobody would ever look. With Copilot, anyone who asks the right question gets it summarized in seconds.
Here are seven things to check first.
1. "Anyone with the link" sharing
Links that work for anyone, including people outside your company, are the most common source of exposure. Find how many exist, which sites they're on and whether they still need to. Consider turning off anonymous links or setting them to expire.
2. Sites and Teams open to everyone
SharePoint sites and Teams that include "Everyone" or "Everyone except external users" are readable by your whole organization, and by Copilot on behalf of anyone. Review them, especially old project sites, HR and finance areas.
3. Sensitive content in the wrong places
Payroll exports, HR files, contracts, board materials and client records tend to end up in shared drives and chat attachments. Find where they live and tighten access before an AI assistant makes them searchable. Sensitivity labels can help protect the most important files.
4. Guest and external accounts
Old guest accounts from past vendors and partners may still have access to sites and files. Remove what's no longer needed.
5. AI and third-party apps with access to your data
Staff can grant apps permission to read mail, files and calendars. Note-takers, browser extensions and AI tools often ask for broad access. Review every enterprise app with consent to your data and remove what you don't recognize or need.
6. Admin accounts and sign-in security
A compromised account with Copilot is a faster compromised account. Make sure every user has strong multifactor authentication, admin roles are limited to the people who need them and admin accounts are protected more strictly than normal ones.
7. A written AI use policy
Before rollout, tell staff what Copilot is for, what data they shouldn't ask it about or paste into other tools, and who to call when it surfaces something it shouldn't. Have them acknowledge it.
Then roll out in stages
Start with a pilot group, watch what they use it for and what they find, fix anything surprising, then expand. A staged rollout is also how you find out whether the licenses are worth paying for.
It isn't one-and-done
New sites, new links, new guests and new apps appear every week. The tenant you cleaned up in March won't look the same in June. Plan to re-check regularly.
Where to start
Our free governance, security and compliance assessment takes about ten minutes and covers AI policy, identity, data sharing and the controls insurers ask about. No system access.
Take the free governance, security & compliance assessment
Our AI Governance, Security & Compliance Program runs a read-only scan of your Microsoft 365 tenant, including oversharing and connected AI apps, gives you a ranked fix list and re-checks every month. See the program.