SharePoint Storage Limits: How the Tenant Pool Is Calculated, What Consumes It, and What to Do When It Runs Out

Microsoft's support article for the out-of-storage condition states the formula: every non-education tenant gets 1 TB plus 10 GB per license of an eligible plan, plus any Office 365 Extra File Storage you have bought. The pool is shared by every SharePoint site in the tenant, including the sites behind Microsoft Teams.

Two worked examples:

• 60 users on Microsoft 365 Business Standard: 1 TB plus 600 GB, roughly 1.6 TB.
• 300 users on Microsoft 365 Business Premium: 1 TB plus 3,000 GB, roughly 4 TB.

The number to watch is in the SharePoint admin center under Active sites, where the top right shows storage used across all sites against the subscription total; Microsoft notes the figure excludes the last 24 to 48 hours and is calculated in binary gigabytes. Individual sites can carry their own limits, but a site limit only divides the pool; it never adds to it.

When the total looks wrong, Microsoft's admin center diagnostic (Run Tests: Tenant Storage) shows how the quota was allocated; the usual cause is a license reduction at renewal, since 10 GB leaves the pool with every license that does.

• Version history. Every saved version of a document counts. Microsoft offers automatic version history limits, where the service thins out older intermediate versions, or manual limits with a major-version count between 1 and 50,000 and an expiry of 30 days or more. Older tenants often carry hundreds of versions of large files, and version overhead is routinely the largest line in the storage exports we run.
• Recycle bins. Deleted files sit in the first-stage and then the site collection recycle bin for up to 93 days and count until they expire; Microsoft's Archive pricing article notes that an archived site's billed size changes when items expire from its recycle bin.
• Teams files. Files in a standard channel live in the team's SharePoint site, and each private or shared channel has its own site. All of them draw from the pool.
• Retention. Content under a retention policy or hold is kept after users delete it. Check the Purview policies before expecting cleanup to reclaim space.
• OneDrive is separate. Each user's OneDrive has its own allocation, managed with the OneDrive default storage setting, which is where Microsoft's add-storage article sends OneDrive questions. Moving files there to escape the pool creates a different problem: a departed user's OneDrive is deleted on a schedule.

Measure before deleting. A metadata export of every file and version in scope, never the contents, ranks the drivers: version overhead, large inactive files, media and disk images, duplicates, non-business file types. That is the method behind our SharePoint Storage Optimization engagement.

1. Set version limits tenant-wide. Turn on automatic version history limits for new libraries, then apply limits to the existing libraries with the largest version overhead. Existing versions are removed only when the trim runs; setting the policy alone does not reclaim space.
2. Retire inactive sites. Ownerless and inactive sites accumulate for years; the SharePoint Governance and Information Architecture Review lists them with last activity, owner and size so the decision is a table, not a hunt. SharePoint Advanced Management can automate retirement, but it is separately licensed.
3. Remove non-business content. Installers, disk images, personal media and old backup sets do not belong in a document library; a Teams governance cleanup usually finds a second copy in an abandoned team.
4. Empty recycle bins last, and only after a retention check. Emptying a site collection recycle bin is irreversible for anything not under hold.

What not to do: raise site quotas (the pool is the constraint), or delete versions of contracts or financial records without a compliance sign-off. Native Microsoft 365 Backup is billed per GB protected, so a bloated tenant costs more there too.

When the content is legitimate and active, the answer is capacity. Office 365 Extra File Storage is the add-on that increases the SharePoint pool. From Microsoft's admin documentation:

• It is bought in 1 GB increments, and the quantity can be reduced later to as low as 1 GB; removing the add-on entirely takes a support request.
• It needs an eligible base plan; Microsoft's list includes the Microsoft 365 Business plans, Microsoft 365 E3, E5, F1 and F3, Office 365 E1, E3 and E5, and SharePoint Plan 1 and 2.
• A tenant that buys through a Cloud Solution Provider cannot buy the add-on directly from Microsoft; the order goes through the partner, and ours is at Microsoft's list price with monthly and annual options shown on the page.
• It adds storage only: no users, apps, mailboxes or OneDrive capacity.

The add-on is the right tool for a working set that is genuinely larger than the pool. It is the wrong tool for a tenant whose pool is 40 percent version history; that money buys the same versions again next year.

Microsoft 365 Archive moves inactive SharePoint sites, and in preview individual files, into a cold tier inside SharePoint. From Microsoft's documentation:

• Archived content stops counting against the active quota, keeps its permissions, metadata and versions, and stays searchable for admins, Purview, eDiscovery and end users. Users cannot open it until it is reactivated.
• It is billed pay-as-you-go through an Azure subscription at $0.05 per GB per month, charged only when archived plus active storage exceeds the tenant's licensed SharePoint quota; a tenant under its quota pays nothing for archiving.
• The reactivation fee was removed on March 31, 2025. A reactivated site cannot be archived again for four months; a reactivated file, for 30 days.
• A team with only standard channels archives normally; one with private or shared channels cannot be archived from the SharePoint admin center. File-level archive is still a preview with client limitations.
• Copilot does not use archived content, a governance benefit in its own right.

Setup is an Azure subscription, pay-as-you-go billing in the Microsoft 365 admin center, and the Archive toggle under Org settings. As with every Microsoft pay-as-you-go service, the meter is billed to you: we configure it, the consumption is yours.

Most tenants end up with cleanup plus one of the two products (the table below compares them), and the Managed SharePoint Online and Intranet Care Plan watches the pool afterwards so the next email does not arrive on a Tuesday.

Does OneDrive count against the SharePoint storage pool?

Not in a paid tenant. OneDrive is allocated per user; the Extra File Storage add-on does not change it. Only a trial tenant pools SharePoint, OneDrive and Exchange Online together.

Why did our quota drop after renewal?

Because the pool is 1 TB plus 10 GB per eligible license: fewer licenses, smaller pool. Add-on storage is unaffected; run Microsoft's Tenant Storage diagnostic to see the allocation.

Do Microsoft Teams files count?

Yes. Standard-channel files live in the team's site, and every private or shared channel is its own site; all of them draw from the pool.

Is Microsoft 365 Archive cheaper than the add-on?

It depends on how much content is inactive. Archive costs $0.05 per GB per month above the licensed quota, but users cannot open archived content until it is reactivated; the add-on keeps everything live at the list price on our page. Microsoft publishes an Archive pricing calculator; run both numbers.

Will cleanup reclaim space immediately?

No. Deleted items count until the recycle bins purge them (up to 93 days) or an admin empties the bins, version limits reclaim space only when the trim runs, and the admin center figure lags by 24 to 48 hours.

• Microsoft Learn (support article): SharePoint Online out of storage space
• Microsoft Learn: Add more SharePoint storage to your subscription
• Microsoft Learn: Overview, Pricing model, Set up, FAQ and Manage articles for Microsoft 365 Archive
• Microsoft Learn: Pay-as-you-go services and pricing (storage services); Microsoft 365 pay-as-you-go services overview
• Microsoft Learn: Set-SPOTenant (version history limit parameters)
• Microsoft Learn: Try or buy a Microsoft 365 for business subscription (trial storage limits); Delete a user from your organization (recycle bin retention)
• IT Partner: SharePoint Storage Optimization and Managed SharePoint Online and Intranet Care Plan service pages

Per-site limits from the SharePoint service description were not consulted; check the current SharePoint limits page for those.