Microsoft 365 Copilot does not disclose your data: it simply accesses what your collaborators can already see. If your SharePoint and OneDrive permissions are not configured correctly, Copilot becomes an inadvertent revealer of your blind spots. Good news: the problem — and the solution — are in your hands.

Copilot does not “leak”, it reveals

When a colleague asks Copilot “What are the team’s latest salaries?” and receives an answer, the temptation is strong to blame the AI. Yet Copilot works exactly as intended: it queries only the files and documents the user can access in your Microsoft 365 tenant.

The real problem is the silent proliferation of access rights. Over the years, HR, financial or strategic files end up shared “with everyone” by mistake, or accessible to entire teams that no longer need them. Without Copilot, these accesses often remained unnoticed. With Copilot, they become visible — and that can be a shock.

The challenge for SMBs: years of unmanaged access

In an SMB of 50 people, SharePoint can accumulate hundreds of sites, libraries and shared folders without a clear policy. Executive documents sit alongside activity reports in Teams spaces that everyone can access “just in case”.

Copilot does not create this mess — it exposes it. And that is precisely why many SMBs hesitate to deploy it: they fear what the AI might “show”. The right approach is the opposite: consider Copilot as a free audit of your data governance.

How to regain control before or after deployment

Microsoft recommends not indefinitely blocking Copilot deployment while waiting for perfect governance — that will never happen. The recommended strategy is progressive:

• Restrict first the “Entire organisation” accesses in SharePoint: identify sites or libraries shared across the tenant and reduce their scope.
• Enable Microsoft Purview (included in Microsoft 365 E3/Business Premium) to automatically classify your sensitive documents and apply sensitivity labels.
• Use the Copilot Dashboard in the Microsoft 365 Admin Centre to visualise which types of content are being queried and adjust your DLP (data loss prevention) policies.

What this means for your SMB

• Act now, even with 10 Copilot licences: start by auditing the 10 most active SharePoint sites and revoke unnecessary “Everyone” accesses.
• Turn the constraint into an opportunity: use the Copilot deployment as a trigger to implement a real data classification policy — a requirement directly related to the GDPR (General Data Protection Regulation).
• Do not wait for perfection: restrict the most sensitive accesses first (HR, Finance, Executive), then roll out Copilot progressively with pilot groups of 10 to 15 users.

Want to discuss this? Get in touch with our Axentys experts.

This article is informative and does not constitute legal advice.