URGENT BUSINESS IMPACT ESCALATION

Run the SharePoint Tenant Storage diagnostic immediately because the sites are already unlocked and the admin center shows tenant capacity available; it checks quota allocation and enforcement issues that the storage display alone does not identify.^1^

Immediate admin actions

1. Sign in to the Microsoft 365 admin center using a Microsoft 365 administrator account.
2. Open Help & support and run SharePoint Tenant Storage.
3. Record or capture:
   • Diagnostic execution time and result.
   • Reported allocated, used, and available storage.
   • Any quota-allocation or enforcement issue detected.
4. Apply any remediation offered by the diagnostic, then rerun it to verify that the issue is cleared. The diagnostic is unavailable in GCC High, DoD, and Microsoft 365 operated by 21Vianet.^1^

SharePoint can place the environment into read-only mode when organizational storage usage exceeds its allocated quota. Microsoft specifically recommends this diagnostic when the organization should have more storage than the admin center reflects.^2^

Do not spend time resetting Teams or OneDrive clients: simultaneous failures across Teams files, OneDrive, and SharePoint indicate a service-side storage/read-only condition rather than an isolated sync client problem.

Check the remaining quota condition

Because the tenant-level display has already been checked, determine whether manual site limits are enabled:

1. Go to SharePoint admin center → Settings → Site storage limits.
2. If it is Automatic, individual manual limits are not the applicable path.
3. If it is Manual:
   • Go to Sites → Active sites.
   • Select representative affected SharePoint, Teams-connected, and OneDrive sites.
   • On General → Storage limit, compare each limit with its current usage.
   • Increase a limit only when that specific site has reached it and sufficient tenant capacity exists.

Storage reporting can be delayed by 24–48 hours, so recent deletion or added capacity might not yet appear in the displayed usage.^3^

If only particular users’ OneDrive sites are over their effective quotas, increase the applicable quota or reduce usage and permanently empty the OneDrive recycle bin. Allow time for SharePoint Online to reevaluate the site, then test upload and editing again.^4^

Check for a Microsoft service event

Go to Microsoft 365 admin center → Health → Service health and review:

• Active issues Microsoft is working on
• Issues for your organization to act on
• SharePoint Online, OneDrive for Business, and Microsoft Teams advisories
• Issue history around the first observed failure

If no matching event exists, select Report an issue from Service health so Microsoft can correlate the tenant’s report with other organizations.^5^

Escalate now if the diagnostic does not restore service

Given the multi-service production impact, open a Microsoft 365 business support request while the diagnostic is running:

1. In the Microsoft 365 admin center, select Help & support.
2. Enter: Tenant-wide SharePoint/OneDrive read-only and quota-exceeded errors despite available tenant storage.
3. If the suggested results do not resolve it, select Contact Support.
4. Choose phone or email, verify the contact details, and submit the request.^6^

Include:

• Incident start time and time zone.
• Number or percentage of affected users.
• Exact errors and screenshots with sensitive information removed.
• Confirmation that affected sites show Active and Unlock.
• Tenant storage total, used, and available values.
• Whether site storage management is Automatic or Manual.
• Tenant Storage diagnostic result and execution time.
• Service Health status and any incident/advisory ID.
• Example affected SharePoint, Teams-connected, and OneDrive site URLs.
• Business impact: Teams file/attachment uploads, OneDrive uploads, and SharePoint uploads are unavailable.
• A request for service-side validation of tenant storage quota allocation/enforcement and read-only state.

If every subscription was purchased through a Microsoft partner, contact that partner; direct Microsoft support access requires at least one subscription purchased from Microsoft.^6^

References

1. Self-help diagnostics for SharePoint Online and OneDrive administrators
2. SharePoint in Microsoft 365 Out of Storage Space - SharePoint
3. Manage site storage limits in SharePoint in Microsoft 365
4. OneDrive site is read-only because storage quota was exceeded
5. How to check Microsoft 365 service health
6. Get support for Microsoft 365 for business