Version Trimming & Retention Policies
Overview
Many Microsoft 365 tenants accumulate significant storage overage in SharePoint Online, OneDrive, and Teams — often driven by unchecked file versioning and the absence of retention policies. Organizations respond by purchasing add-on storage at $0.20/GB/month, which compounds into thousands of dollars annually. Patriot Consulting helps clients reclaim this spend through two proven approaches: SharePoint Version Trimming (using built-in PowerShell trim jobs to purge excess file versions) and Microsoft Purview Retention Policies (automating deletion of aged content across SharePoint, OneDrive, and Teams). Both methods reduce consumed storage without impacting active data or end-user workflows.
Case Study — Consumer Food Manufacturer
Patriot Consulting identified that a consumer food manufacturer was paying for over 12 TB of add-on SharePoint storage, the majority of which was consumed by historical file versions rather than active documents. Using SharePoint Online version trim jobs, we targeted their 14 largest site collections and reclaimed 12,247 GB (~12 TB) in 19 calendar days:
Storage Metrics
- Storage reclaimed via version trimming: 12.0 TB
- Add-on storage cost eliminated: $2,449/mo
- Annual savings at $0.20/GB/month: $29,394/yr
- Total elapsed time for all 14 sites: 19 days
Site Storage Reclamation Table
| Site | Date Range | Days | GB Trimmed | Monthly Savings |
|---|---|---|---|---|
| Site 1 | Oct 28-Nov 16 | 19 | 8,291.9 | $1,658 |
| Site 2 | Nov 5-Nov 8 | 3 | 2,679.2 | $536 |
| Site 4 | Nov 5-Nov 6 | 1 | 469.0 | $94 |
| Site 3 | Nov 5-Nov 9 | 4 | 291.2 | $58 |
| Sites 5-14 | Nov 5-Nov 8 | 1-2 | 515.9 | $103 |
| Total | 12,247.4 | $2,449 |
Two Paths to Reduce M365 Storage Costs
How to Assess Your Storage Overspend
| Approach | How It Works | Best For |
|---|---|---|
| Version Trimming (SharePoint PowerShell) | Run trim jobs via New-SPOSiteFileVersionBatchDeleteJob to permanently remove excess file versions by age or count threshold. A What-If analysis can be run first to preview impact before committing. Processing runs at ~2.25 days/TB. | Immediate storage reclamation where version bloat is the primary driver. No change to active files. |
| Purview Retention Policies (Microsoft-funded workshop) | Define org-wide or site-level retention policies in Microsoft Purview that automatically delete content after a specified period (e.g., 3 years). Applies across SharePoint, OneDrive, Teams channels, and chats. Patriot delivers this via a Microsoft-funded Data Governance Workshop at no cost to the client. | Ongoing governance to prevent future storage growth. Also addresses compliance and data lifecycle requirements. |
Steps to Implement
| Step | Action |
|---|---|
| 1 | Open the SharePoint Admin Center > Active sites. Sort by Storage used descending to identify your largest sites. |
| 2 | Run a Version Storage Usage Report on your top sites using New-SPOSiteFileVersionExpirationReportJob to quantify how much storage is consumed by file versions versus current files. |
| 3 | Run a What-If analysis to preview the impact of trimming with your chosen mode (expire by age, count limit, or automatic). This is non-destructive and produces a CSV report. |
| 4 | Calculate your potential savings: multiply reclaimable GB by $0.20/month (the M365 add-on storage rate) and annualize. Contact Patriot to schedule a Microsoft-funded Purview Data Governance Workshop for retention policy design at no cost. |
Conclusion
Patriot Consulting offers a Microsoft-funded Purview Data Governance Workshop that designs retention policies for your environment plus hands-on version trimming engagements that deliver measurable savings within 30 days.