The behavior is caused by Copilot enforcing usage limits that are controlled at the service/tenant level, not by the local Excel file. Even if there has not been much visible interaction, background or earlier Copilot requests can count toward the daily quota. When that quota is reached, Copilot shows a message such as “You’ve reached your limit for today” across Excel and other Microsoft 365 apps until the limit window resets.
Because this is an organization (local government) tenant, limits and access can also be affected by:
- Licensing and account conflicts (for example, multiple accounts signed in, or Copilot not validating correctly).
- Organizational policies that restrict or throttle Copilot usage.
- Network or privacy settings that interfere with Copilot’s ability to validate the license and requests.
Concrete steps:
- Confirm the correct work account is the primary signed-in account in Excel and other Microsoft 365 apps.
- Close all Microsoft 365 apps and sign out, then sign back in with the work account and try Copilot again after some time has passed (to allow any quota window to reset and licenses to revalidate).
- If the issue persists, contact the organization’s Microsoft 365 admin or IT help desk so they can:
- Verify that the account has a Copilot-supported license and that Copilot is not blocked by organizational policies.
- Check for any tenant-level limits or issues affecting Copilot usage.
- Open a support case with Microsoft if needed.
References: