Worried that Copilot could surface overshared company data?

IT Desk can review your Microsoft 365 permissions, SharePoint structure, identity controls and data governance before Copilot is introduced. We’ll help identify overshared information, improve access controls and build a safer foundation for AI adoption.

What information can Microsoft 365 Copilot access?

Microsoft 365 Copilot uses Microsoft Graph and other Microsoft 365 services to provide answers based on the user’s work context.

Depending on the user’s permissions and licence, this can include information from:

• SharePoint

• OneDrive

• Microsoft Teams

• Outlook

• Word

• Excel

• PowerPoint

• Meetings, emails and calendars

• Approved Microsoft 365 Copilot connectors

Microsoft confirms that Copilot only accesses information that the individual user is authorised to access. If a user cannot open a file, site, email or conversation through their normal Microsoft 365 account, Copilot should not be able to use that content in its response.

Does Copilot give employees new access to files?

No. Copilot does not normally give an employee permission to access content they could not already open.

For example:

• A member of the sales team should not be able to access a restricted HR folder unless they have already been granted access.

• An employee cannot use Copilot to read another person’s private OneDrive files unless those files have been shared with them.

• A user who is not a member of a restricted Teams workspace should not receive information from that workspace.

• Removing a user’s access to a file or site also removes Copilot’s ability to use that content for the user once the permissions change has taken effect.

Copilot inherits the permissions and security controls already present in Microsoft 365. This is reassuring, but it also means that Copilot inherits any existing permission mistakes.

Why can Copilot still create a data-security concern?

Many Microsoft 365 environments contain files that have been shared too widely over time.

Common examples include:

• SharePoint sites that all employees can access

• Documents shared using organisation-wide links

• Former project members who still retain access

• Old Teams workspaces that are no longer actively managed

• Sensitive files stored in general-purpose folders

• External guests who no longer require access

• Duplicate and outdated documents with inconsistent permissions

Before Copilot, an employee might technically have access to this information without knowing where it was stored or what to search for.

Copilot can make accessible information much easier to discover, summarise and combine. It does not create the underlying oversharing, but it may expose permissions that were already too broad.

This is why a Microsoft Copilot readiness assessment should examine data access and governance rather than focusing only on licences and user training.

Examples of what Copilot may and may not access

Does Microsoft use company data to train its AI models?

Microsoft states that prompts, responses and data accessed through Microsoft Graph are not used to train the foundation models that power Microsoft 365 Copilot.

Microsoft 365 Copilot operates within Microsoft’s commercial data-protection and compliance commitments. This differs from employees copying company information into an unapproved public AI service, where the organisation may not have the same contractual or technical protections.

Businesses should still establish an AI usage policy explaining:

• Which AI tools employees may use

• What information can be entered into them

• Which Copilot features are approved

• How sensitive information should be handled

• Who is responsible for reviewing agents and connectors

• How potential data incidents should be reported

Can Copilot access data through connectors and agents?

Copilot connectors can allow Microsoft 365 Copilot to use information from approved external systems.

The answer depends on how the connector is configured. Microsoft allows connectors to respect the source system’s access-control lists, but some connectors can also be configured so their content is visible more broadly.

Before enabling a connector or agent, administrators should review:

• Which data source it connects to

• Which users can discover the information

• Whether existing source-system permissions are respected

• Which actions the agent can perform

• Who owns and reviews the connector

• Whether the connection is still required

A poorly configured connector can expand the information available to Copilot, so connectors should not be enabled without a clear permissions review.

How should a business prepare its data for Copilot?

Before a wider rollout, review the following areas:

SharePoint and OneDrive permissions

Identify sites and folders with broad access, organisation-wide sharing links, unmanaged guests or outdated membership.

Microsoft Teams access

Review old teams, private channels, shared channels and former project members. Archive or remove content and access that are no longer needed.

Sensitive information

Use appropriate sensitivity labels, retention policies and data-loss-prevention controls where the organisation’s licensing and requirements support them.

User identities

Enforce multifactor authentication and appropriate access policies. Copilot relies on the identity of the person making the request, so compromised accounts remain a serious risk.

Data quality

Remove or archive obsolete and duplicated information. Copilot may produce less reliable answers if it finds multiple conflicting versions of a document.

Ongoing governance

Permissions should be reviewed regularly rather than only during the initial rollout. New sites, files, teams, agents and connectors can introduce additional access over time.

IT Desk can help organisations improve their underlying Microsoft 365 and SharePoint environments before deploying Copilot more widely.

Can an administrator stop certain content appearing in Copilot?

Administrators can control access through existing SharePoint, OneDrive, Teams and Microsoft 365 permissions.

Microsoft also provides governance features such as restricted access controls, data-access governance reports, sensitivity labels and Restricted Content Discovery. Restricted Content Discovery can temporarily prevent high-risk SharePoint sites from appearing in organisation-wide Copilot experiences while permissions are reviewed.

Microsoft advises using discovery restrictions selectively because excessive restrictions may reduce the relevance and completeness of Copilot’s responses. Correcting the underlying permissions and governance remains the more sustainable approach.

Can Copilot see another employee’s OneDrive?

Not automatically. Copilot can only use another employee’s OneDrive content if the user already has permission to access it—for example, because the file or folder was shared with them.

Can Copilot read private Teams messages?

Copilot can use Teams content available to the individual user. It should not provide access to private conversations or workspaces that the user is not authorised to view.

Will Copilot reveal confidential HR or finance documents?

Not if those documents are properly restricted to authorised users. However, if an HR or finance file has accidentally been shared too widely, Copilot may make that existing oversharing easier to discover.

Should permissions be reviewed before enabling Copilot?

Yes. Businesses should review SharePoint, OneDrive, Teams, guest access and organisation-wide sharing before enabling Copilot broadly. This reduces the risk of existing oversharing becoming more visible.