Microsoft 365’s storage model looks generous in the small print of the license agreement: 1 terabyte per user for OneDrive, plus a pooled SharePoint allocation of 1 TB plus 10 GB per licensed user. A 500-seat organization gets 6 TB of SharePoint storage included. That sounds like more than enough.
It rarely is, once you account for how organizations actually use Microsoft 365 over time. SharePoint becomes the repository for every team collaboration, every department document library, every intranet page, every video recording from Teams meetings. OneDrive becomes the sync target for every employee’s desktop and documents folder. Four or five years into a Microsoft 365 deployment, storage consumption routinely exceeds what the standard licensing model includes — and Microsoft’s overage pricing is not listed prominently on any invoice.
Understanding where the costs accumulate is the first step to managing them.
The Teams recording problem
The single largest driver of unexpected SharePoint storage growth in most Microsoft 365 tenants is Teams meeting recordings. When Teams recordings are enabled without a policy, every meeting recording is automatically stored in the recorder’s OneDrive (for personal meetings) or in the SharePoint site associated with the Teams channel (for channel meetings). A 60-minute Teams meeting recording typically produces a 500 MB to 1 GB video file.
An organization with 500 people, where each employee participates in 5 recorded meetings per month, generates 2.5 TB of video data monthly — or 30 TB per year. Much of this is recordings of routine standups, project check-ins, and status updates that nobody will watch after the first week.
Without a retention policy, these recordings accumulate indefinitely. The SharePoint storage report (Admin Center > SharePoint > Storage) will show this growth clearly. In organizations that have had Teams enabled for two or more years, it is common to find SharePoint storage consumption where 40 to 60 percent of the total is meeting recording files.
The fix is a combination of a Teams meeting recording policy (90-day automatic deletion is a reasonable default for most meeting types, with longer retention for defined categories like training or compliance recordings) and a user communication campaign. The Microsoft Purview compliance portal supports retention policies specifically scoped to video content from Teams.
OneDrive: the desktop sync accumulation problem
OneDrive’s 1 TB per user allocation seems unlimited. It isn’t when employees use OneDrive as a complete backup of their local drives, including development environments, local application caches, large media files, and downloaded archives.
The OneDrive Known Folder Move feature, which redirects Desktop, Documents, and Pictures folders to sync with OneDrive, is a sensible business continuity measure. However, when enabled without guidance on what belongs in those folders, it captures everything — including gigabytes of files that have no business value and no reason to be in cloud storage.
OneDrive per-user storage consumption is visible in the Microsoft 365 Admin Center under Users > Active Users (select any user, then OneDrive settings) or via Graph (/reports/getOneDriveUsageAccountDetail). The distribution is always uneven: a small percentage of users (often developers, video editors, or data analysts) consume a disproportionate share of the total allocation. Those users are the right starting point for a storage rationalization conversation, not a blanket policy.
SharePoint document library housekeeping
SharePoint sites, unlike email inboxes, rarely trigger the sense of urgency that drives cleanup. Email feels overwhelming when unmanaged; SharePoint files sit invisibly in libraries while the site count and storage continues to grow.
Several categories of SharePoint sites deserve specific attention in a storage audit:
Orphaned sites. SharePoint sites created for projects, working groups, or Microsoft Teams channels that are no longer active. Owners have left the organization or the group has disbanded. These sites continue to consume storage and represent an information governance risk. Microsoft provides a Sites Without Owners report in the SharePoint Admin Center.
Archived project sites. Sites with no recent activity (last 90+ days) but active ownership. These may need to be retained for reference but don’t need to be in the standard storage pool. Microsoft 365 Archive (currently in preview, pricing at $0.05/GB/month) provides a cost-effective tier for read-only access to archived content.
Large video libraries. SharePoint document libraries used to store video content outside of Stream proper. Large video libraries in team sites are common after content migrations and are significant storage consumers. These should be moved to Microsoft Stream, which has its own storage governance, or archived.
Version history bloat. SharePoint maintains version history for documents by default — up to 500 major versions. For document libraries with heavy editing activity, version history can consume 3 to 5× the size of the current file versions. Most organizations don’t need 500 versions of a spreadsheet. Setting a version limit (20 major versions is a practical default for most document types) significantly reduces storage growth without impacting business use.
Reading the SharePoint storage report
The SharePoint Admin Center provides a site-level storage consumption report that shows current storage used, storage allocated, the percentage consumed, and the last activity date. This report is the starting point for any storage rationalization effort.
Sites consuming more than 100 GB deserve investigation. Sites with high storage consumption and no activity in the last 90 days are orphaned candidates. Sites with rapidly growing storage and an active team are candidates for a storage lifecycle policy conversation with the site owner.
The aggregate view — total consumed vs. total included in your license — tells you whether you are approaching overage. At $0.20/GB/month in overage charges, a 10 TB overage is $24,000 per year. Most organizations approaching that threshold can recover a significant portion through the housekeeping practices above without any impact to business operations.
Storage governance is not glamorous, but at scale it is a meaningful cost lever. The organizations that treat SharePoint and OneDrive storage with the same discipline they apply to cloud object storage — lifecycle policies, retention rules, tiering — consistently find that their Microsoft 365 storage costs remain predictable and aligned with actual business value rather than growing without bound as the organization scales.