SharePoint Remains Read-Only After Freeing Up Storage – Is Purchasing Additional Storage Mandatory?

Microsoft’s published policy does not require purchasing additional storage after a second quota overage; deleting content, archiving content, or adding capacity are documented alternatives for bringing the tenant below its quota.^1^

Restore write access

Because both recycle-bin stages have already been cleared, proceed with these checks rather than repeating the cleanup.

1. Verify the authoritative tenant storage value
   • Sign in as a SharePoint Administrator.
   • Open SharePoint admin center → Sites → Active sites.
   • Check the storage bar in the upper-right corner.
   • Confirm that total usage is now below the approximately 3.2 TB entitlement.
   SharePoint’s displayed storage usage does not include changes made within the previous 24–48 hours, so deletion of 1.2–1.5 TB might not yet be reflected.^2^
2. Allow the storage calculation to update
   • If the cleanup occurred less than 48 hours ago, allow up to 48 hours and check the Active sites storage bar again.
   • Test creating or editing a small file only after that bar shows available capacity.
   There is no documented requirement to purchase temporary storage merely because this is the tenant’s second overage.
3. Check whether an individual site quota is still exceeded
   • In SharePoint admin center → Settings → Site storage limits, determine whether storage management is Automatic or Manual.
   • If it is Manual, go to Sites → Active sites, select each affected site, and examine General → Storage limit.
   • If a site’s usage exceeds its individual limit, increase that site’s limit using capacity already available in the tenant, or switch storage management to Automatic if that matches your organization’s management model.
   • Save the change and retest after it propagates.
   Under automatic management, sites draw from the central tenant pool. Under manual management, a site can reach its own configured limit even when the tenant still has available space.^2^

If usage does not fall as expected

A retention policy or retention label can preserve deleted content in the hidden Preservation Hold library. Such retained content can therefore prevent storage from decreasing as quickly as the visible deletion suggests. Cleanup of eligible content is performed by a periodic timer job; depending on retention configuration, deletion from the Preservation Hold library can take up to 37 days.^3^

Have the Microsoft Purview administrator review the affected sites’ retention policies and labels. Do not remove or weaken a retention policy solely to reclaim storage without approval from the organization’s compliance or records-management owner.

If capacity is available but sites remain read-only

After the storage report shows the tenant below quota and the 24–48-hour reporting interval has passed:

1. Note the exact banner or error shown on an affected site.
2. If it says “SharePoint sites are read-only right now while we do some maintenance” or returns 403 Forbidden, check whether that site has a separate lock state. Microsoft documents a site lock as a distinct possible cause of these messages.^4^
3. Also check Microsoft 365 admin center → Health → Service health and Health → Message center for an active SharePoint incident or maintenance notice.
4. Run the SharePoint tenant storage diagnostic described in Microsoft’s out-of-storage article. It requires a Microsoft 365 administrator account and is unavailable for GCC High, DoD, and Microsoft 365 operated by 21Vianet.^1^
5. If the diagnostic shows no quota problem but write access remains blocked, open Microsoft 365 admin center → Help & support and request Microsoft Support to verify the tenant’s backend quota and lock state. Include:
   • Current entitlement and displayed usage
   • Date and approximate volume of deletion
   • Confirmation that both recycle-bin stages were cleared
   • Affected site URLs
   • Exact read-only messages
   • Screenshots of the storage bar and site storage settings

Additional storage is necessary only if actual active storage remains above entitlement and sufficient content cannot be deleted or archived—not because the limit was exceeded for a second time.

References

1. SharePoint Online out of storage space
2. Manage site storage limits in SharePoint in Microsoft 365
3. Learn about retention for SharePoint and OneDrive
4. SharePoint or OneDrive read-only error messages