SharePoint Online global storage limits

Tenant storage = 1TB base + 10GB per licensed user. No published maximum cap - keep adding licenses or purchase storage add-ons. Per-site limit is 25TB. Check usage in SharePoint Admin Center → Active Sites → Storage. Happy to help plan your storage strategy!

Best, 

Ahmed Masoud

LinkedIn

In SharePoint Online, your tenant storage is calculated as 1 TB + 10 GB for every licensed user. Each individual site (site collection) can grow up to 25 TB, but the total tenant storage is capped by this formula. If you keep adding licenses, you keep adding 10 GB each there’s no fixed “hard cap” other than the practical maximum of licenses you can purchase.

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There is a limit for the amount licenses a tenant can purchase (which adds 10GB/license to the default 1TB) depending on the type of subscription being used (Or type of tenant that is).

For example:
Tenants that are using any of the Microsoft 365 Business (Basic, Standard, Premium) Teams Essentials, (MSA & Microsoft Entra ID) can only purchase up to 300 licenses. That would be 500k for Enterprise tenants.

See: https://learn.microsoft.com/en-us/office365/servicedescriptions/sharepoint-online-service-description/sharepoint-online-limits

If you have more than 500,000 users, contact a Microsoft representative.

There is no publicly stated upper limit for Enterprise tenants.

Some mega-scale organizations are believed to be in the 600k–1M+ user range, but those details are never made public.