SharePoint Storage Limits for UK SMEs: What You Get and How to Avoid Paying More

SharePoint storage looks generous until the day a site stops accepting uploads. We have watched a 40-person business in Northamptonshire hit that wall during a busy tender week, when the estimating site quietly flipped to read-only because the tenant pool was full. Nobody had bought extra storage. Nobody had been warned. The files simply would not save.

That scenario is avoidable, and it starts with knowing exactly what you are entitled to and what quietly eats it.

What SharePoint storage you actually get

Every Microsoft 365 tenant gets a pooled SharePoint allocation, not a per-site allowance. The formula Microsoft publishes is 1 TB for the organisation plus 10 GB for each licence that includes SharePoint. A 25-user business therefore has 1.25 TB to share across every site, every Teams channel folder and the preservation hold library. A 100-user business has 2 TB.

OneDrive is separate. Each user gets their own OneDrive storage, and it does not draw on the SharePoint pool. That distinction matters when you are trying to work out why your numbers do not add up.

Frontline plans (F1 and F3) are the exception. They get a flat 1 TB with no per-user addition, which catches out organisations that mix frontline and office licences.

Returning licences shrinks the pool. If you let go of 30 licences after a restructure, you lose 300 GB of allocation at the next recalculation while the data stays exactly where it is. We have seen tenants land over quota purely because someone tidied up the licence count.

The limits that catch people out

Storage is the headline number, but five smaller limits cause most of the day-to-day pain.

Version history is where storage hides

Every major version of a document is stored as a complete copy. A 5 MB spreadsheet edited 100 times can hold 500 MB of history for a single file. Multiply that across a finance library and the numbers get silly fast. Finance teams are usually the worst offenders because their spreadsheets are edited daily.

Microsoft sets new document libraries to keep 500 major versions by default, a figure chosen when files were small and edits were occasional. It is far too generous for a modern tenant where autosave fires every few seconds. Microsoft's own storage guidance now recommends setting organisation version history limits to Automatic, and that is the setting we change first on almost every tenant review.

The recycle bin counts against you

When someone deletes a file it sits in the site recycle bin for 93 days, and that space is still charged to your organisation's pool. Teams meeting recordings and superseded project files often sit there for months, invisible in day-to-day use but very visible on the storage report.

What happens when the pool fills

Microsoft does not quietly add storage when you run out. Sites that exceed the tenant allocation are placed in read-only mode, and users cannot add or edit content until space is freed or capacity is bought. Classic site creation and site creation through PowerShell are blocked as well. The warning signs arrive through quota alerts, but only if somebody has configured them.

Set warning thresholds at 80 percent of each site quota and make sure the alerts reach a monitored mailbox rather than an admin who left two years ago. That single setting has saved more pain across the tenants we manage than any other storage control.

Where the space actually goes

Three things dominate most storage audits we run. Version history on high-churn libraries sits at the top. Dormant project sites that were never closed come second. Cold data that should have been archived years ago comes third. Everything else, from oversized files to forgotten Teams recordings, adds a few percent.

Teams deserves a special mention. Every team creates a SharePoint site, and every channel folder lives in it. A business that has spun up 60 teams over four years has 60 sites, most of them dead, all of them drawing on the same pool. Nobody deliberately created that sprawl. It just happened, one project at a time.

What extra storage actually costs in the UK

Microsoft sells additional SharePoint storage in 1 GB increments, with no upper cap. The published US rate is $0.20 per GB per month. UK resellers sell the same add-on, called Office 365 Extra File Storage, at roughly £0.15 to £0.20 per GB per month ex VAT depending on commitment and partner. Treat those as indicative ranges and check your own quote, because reseller pricing moves.

At £0.16 per GB per month, 1 TB of extra storage costs around £160 a month, or roughly £1,920 a year. That is real money for an SME, and it is the number to hold in your head when someone suggests simply buying more space.

Microsoft 365 Archive is the better option for content you must keep but rarely open. It moves inactive sites to a cold tier at roughly a quarter of the overage rate, and the data stays inside your Microsoft tenant. One caveat: restoring an archived site more than seven days after archiving carries a reactivation charge per GB, so archive decisions should be deliberate.

How to cut storage before you buy more

Work through these in order. Cleaning up before archiving matters, because archiving a bloated site locks the wasted versions into the cold tier and you keep paying for them.

• Check the Active sites report in the SharePoint admin centre and note the top 20 sites by usage. They usually account for most of the pool.
• Lower the major version limit on high-churn libraries from 500 to 25 or 50, then run a version cleanup so existing history is trimmed too.
• Set organisation version history limits to Automatic so new libraries start with a sane cap.
• Empty the site recycle bins, then the second-stage bin at tenant level.
• Find orphaned OneDrive accounts belonging to people who have left, and apply a retention policy to close them down.
• Archive sites with no meaningful activity in 12 to 24 months instead of deleting them.
• Set site storage quotas so one project site cannot swallow the whole pool.

What to fix permanently

Cleanups are a project. Governance stops the problem returning. Set version limits at the point a library is created, put a quarterly storage review on the IT calendar, and give site owners a simple rule: if it has not been opened in a year and you are not legally required to keep it, archive it.

We do this work as part of a SharePoint consultancy engagement, and the storage conversation is usually the easy part once the report is on the table.

What we would do

Buying storage is the lazy answer, and it is the expensive one. Most UK SMEs we assess are sitting on 30 to 40 percent of reclaimable space that nobody has looked at, and the fix costs nothing but an afternoon of careful work. Paying £1,900 a year for a terabyte you did not need is a choice, not a requirement.

There is one genuine exception. If your business legitimately holds large volumes of video, CAD or scanned records and you have already trimmed versions and archived the cold data, buying storage is the correct call. The mistake is reaching for the add-on before you have done the cleanup. We have signed off extra storage for exactly that reason more than once.

Start with a storage report, not a purchase order. Look at the Active sites page, sort by usage, and see where the space actually went. If the top three sites account for half your pool, you have your answer, and it is not a new invoice from Microsoft.