Quick-reference pricing and base quota figures for Microsoft 365 Extra File Storage, the add-on SharePoint admins buy when the included tenant pool runs short.
| Add-on | Price (USD) | Unit | Annual equivalent |
|---|---|---|---|
| Microsoft 365 Extra File Storage | $0.20 per GB per month | 1 GB minimum; sold in 1 GB increments | $2.40 per GB per year |
What is Microsoft 365 Extra File Storage?
Microsoft 365 Extra File Storage is a per-tenant add-on subscription that increases the pooled storage available to SharePoint Online. Every commercial tenant gets a base allocation included with their plan licences. When that pool fills, admins have two choices: buy more quota through the Extra File Storage add-on, or reduce consumption by cleaning up version history, large files, and recycling bin contents.
Storage is pooled across the tenant. Individual site collections draw from the same shared pool, so a single site consuming excessive version history can push the entire tenant toward its limit.
Base storage included in common Microsoft 365 plans
Before deciding whether to purchase extra storage, confirm how much is already included in your plan.
| Plan | Base tenant pool | Per-user addition | Example: 100 users |
|---|---|---|---|
| Microsoft 365 Business Basic | 1 TB | 10 GB per licensed user | 2 TB total |
| Microsoft 365 Business Standard | 1 TB | 10 GB per licensed user | 2 TB total |
| Microsoft 365 Business Premium | 1 TB | 10 GB per licensed user | 2 TB total |
| Microsoft 365 E1 / E3 / E5 | 1 TB | 10 GB per licensed user | 2 TB total |
| Microsoft 365 F1 / F3 (Frontline) | 1 TB | 10 GB per licensed user | 2 TB total |
| SharePoint Online Plan 1 | 1 TB | 10 GB per licensed user | 2 TB total |
| SharePoint Online Plan 2 | 25 TB | 10 GB per licensed user | 26 TB total |
For a more detailed breakdown of plan-level quotas, see the Microsoft 365 plan storage quota reference.
Buy or clean up? A decision framework
The $0.20 per GB per month price sounds modest. A 100 GB top-up is only $20 per month. But version history grows continuously unless actively managed: a 100 GB purchase this month can become a 500 GB need within two years on an actively used tenant. The table below shows the cumulative cost of buying vs. cleaning up.
| Scenario | Year 1 cost | Year 3 cost | Outcome |
|---|---|---|---|
| Buy 200 GB now, do nothing about version history | $480 | $1,440+ | Storage needs keep growing; quota top-ups become recurring |
| Trim version history with Space Master, no extra purchase | $0 extra | $0 extra (with annual trimming) | Recovered storage typically exceeds the immediate need; managed ongoing |
| Trim first, then buy 50 GB for genuine long-term growth | $120 | $360 | Smaller, stable purchase covering real growth rather than accumulated waste |
When buying extra storage makes sense: the tenant is approaching quota, the content causing the issue is genuine business content that cannot be trimmed (large project deliverables, video archives, compliance-locked records), and the need is confirmed as permanent rather than accumulated waste.
When cleaning up first makes more sense: the quota pressure is driven by version history on libraries with no version limit set, by files in the recycling bin that are past their useful recovery window, or by large image files embedded in Site Pages and document libraries. All three are recoverable without any additional Microsoft spend.
See how Space Master recovers SharePoint storage
How to check your current SharePoint storage usage
Two places in the Microsoft 365 admin centre show storage consumption.
| Location | What it shows | Path |
|---|---|---|
| SharePoint admin centre | Total tenant pool usage vs. available quota | SharePoint admin centre > Settings > Site storage limits |
| Site storage report | Storage used per site collection | SharePoint admin centre > Sites > Active sites > Storage column |
| Report Master (ShareMaster) | Per-site breakdown: live content, version history, recycling bin | Report Master > Export to Excel > Storage tab |
The built-in admin centre view shows total per-site storage but does not separate version history from live content. That distinction matters: a site showing 120 GB in the admin centre may carry 90 GB of version history that could be trimmed without losing any live content. Report Master's per-library breakdown makes that split visible, so you can prioritise where to clean first.
For guidance on reducing storage consumption systematically, see the SharePoint storage reduction guide.
Frequently Asked Questions
How much does Microsoft 365 Extra File Storage cost per GB?
$0.20 USD per GB per month, or approximately $2.40 per GB per year at standard Microsoft list pricing. Sold in 1 GB increments. Regional pricing and CSP partner pricing may differ from the list price.
Does Microsoft 365 Extra File Storage apply to SharePoint and OneDrive?
Yes. Microsoft 365 tenant storage is pooled, and Extra File Storage increases the shared pool available to both SharePoint Online and OneDrive for Business. Individual site collections and personal drives all draw from the same tenant pool.
What is the fastest way to free up SharePoint storage without buying more?
Version history trimming is typically the largest single recovery opportunity. Actively edited libraries often carry 40 to 60 or more versions per file with no version limit set. Trimming to 10 to 20 versions with Space Master's Version Trimmer can recover 40 to 70 percent of total tenant storage without removing any live content. Recycling bin cleanup and image reduction add further gains.
Read the version history trim guide to see the step-by-step process before deciding whether to purchase extra storage.