File share migrations to OneDrive and SharePoint Online are one of the highest-volume collaboration migrations of the decade. The technology is mature, Microsoft provides a free tool that handles most of the data movement, and FastTrack covers the data movement cost for eligible customers. The cost overruns happen not in the data movement but in the permission mapping, the end-user readiness work, and the source-side decommission. This page is the 2026 cost reference for file share migration to OneDrive and SharePoint Online.
The first decision in any file share migration is which content goes to which destination. The three destinations have different cost shapes, different storage limits, and different collaboration patterns. Getting this decision right at the assessment stage avoids re-migration cost later.
Destinations for file share content
| Destination | Content fit | Storage included | Cost per GB over allowance |
|---|---|---|---|
| OneDrive for Business | Personal, home folders, work-in-progress | 1 TB per user (E3+), expandable to 5 TB | $0.20 per GB-month at scale |
| SharePoint Online (site collections) | Departmental, project, knowledge base | 1 TB plus 10 GB per licensed user pool | $0.20 per GB-month |
| Microsoft Teams (built on SharePoint) | Collaborative project shares, channel files | Shared with SharePoint allowance | $0.20 per GB-month |
| Azure Files (for legacy lift-and-shift) | Legacy applications that cannot migrate to SP | Pay-as-you-go | $0.06 to $0.16 per GB-month |
Microsoft's SharePoint Migration Tool is the free baseline tool for file share to OneDrive and SharePoint Online migration. It supports sources of file shares (SMB), SharePoint Server (2013, 2016, 2019, Subscription Edition), and Google Drive. SPMT handles discovery, scanning, content movement, permission mapping (basic), and incremental updates. The tool is documented in the public SPMT documentation.
SPMT scales to large migrations. Microsoft documents support for migrations of 100 TB+ using parallel SPMT workers; the practical limit is the source network bandwidth and the parallel worker count, not the tool itself. For most mid-enterprise migrations under 50 TB, SPMT handles the data movement adequately. Above 50 TB, or where complex permission scenarios or non-standard source systems exist, third-party tools typically pay for themselves in reduced operational complexity.
Three tools dominate the third-party file share migration market: AvePoint Fly, BitTitan MigrationWiz, and ShareGate Migrate. Each has different pricing models and different strengths.
Third-party file share migration tools, 2026
| Tool | Pricing model | Mid-enterprise cost band | Strongest use case |
|---|---|---|---|
| SharePoint Migration Tool (Microsoft) | Free | $0 | Standard file share to OneDrive/SP |
| ShareGate Migrate | Per-user perpetual or annual | $15K to $80K | SharePoint to SharePoint migration; complex permission scenarios |
| BitTitan MigrationWiz | Per-user one-time | $8K to $50K | Mixed source migration (Box, Dropbox, Google Drive) |
| AvePoint Fly | Per-user-licence-month | $20K to $120K | Tenant-to-tenant; regulated/governance-heavy migration |
| Quest On Demand Migration | Per-user one-time | $15K to $90K | Large enterprise; merger/acquisition tenant consolidation |
| Metalogix Content Matrix (Quest) | Per-user perpetual | $25K to $120K | Legacy SharePoint (2007, 2010) source migration |
On-premise file shares carry Windows NTFS permissions inherited from Active Directory security groups. The permission model is hierarchical: each folder has an Access Control List (ACL) listing the groups or users that can read, write, modify, or take ownership of the folder. Permissions inherit from parent folders unless explicitly broken. Custom permissions, removed inheritance, and historical permissions accumulated over a decade create a permission landscape that is rarely fully understood.
OneDrive and SharePoint Online use a different model. OneDrive uses per-file or per-folder sharing permissions, with optional permissions inheritance from the folder structure. SharePoint Online uses site-level permissions via SharePoint groups or Microsoft 365 groups, with optional per-document overrides. The mapping from NTFS to SharePoint is rarely one-to-one: a single NTFS permission can map to multiple SharePoint permissions, or to none if the SharePoint model does not have an equivalent.
The practical approach to permission mapping. First, discover the source permissions (typically via icacls dumps or third-party scanners like AvePoint Insights). Second, decide the destination permission model (mirror the source as closely as possible vs rationalise to a simpler SharePoint model). Third, build the destination groups (Microsoft 365 groups or SharePoint groups) before migration. Fourth, validate permission application on a sample migration. Fifth, run the production migration with the validated mapping.
The permission mapping rule of thumb
The per-TB cost band varies widely depending on permission complexity, source system, and destination split. The decomposition below is for a mid-market 10 TB file share migration with average complexity:
Per-TB cost decomposition, mid-market file share migration
| Line item | Per-TB cost | Notes |
|---|---|---|
| Discovery and scanning | $200 to $500 | Source inventory, content scanning, type analysis |
| Permission audit and mapping design | $400 to $1,200 | The largest single line in most migrations |
| Migration tooling licensing | $150 to $800 | $0 if using SPMT; higher with third-party |
| Data movement labour | $300 to $700 | Per-batch supervision, error handling |
| Validation and reconciliation | $200 to $600 | Spot-check permissions, content integrity |
| End-user training and change management | $150 to $400 | Briefings, helpdesk preparation |
| Source decommission preparation | $100 to $300 | Lock-down, redirect, eventual decommission |
| Per-TB total | $1,500 to $4,500 | Excluding extreme permission complexity |
A representative cost build for a mid-enterprise 50 TB file share migration with 20 TB to OneDrive (home folders, 2,500 users) and 30 TB to SharePoint Online (departmental shares, 200 site collections). Partner-led with FastTrack support for the core data movement, ShareGate Migrate for permission-heavy departmental shares.
Worked file share to OneDrive/SP cost build, 50 TB, 24 weeks
| Cost line | Low estimate | Typical estimate | High estimate |
|---|---|---|---|
| Assessment and discovery (full content inventory) | $25,000 | $45,000 | $95,000 |
| Permission audit (icacls dump and analysis) | $30,000 | $70,000 | $160,000 |
| Destination design (site collections, M365 groups) | $18,000 | $40,000 | $95,000 |
| ShareGate Migrate licensing (12 months) | $15,000 | $40,000 | $80,000 |
| OneDrive home folder migration labour (20 TB) | $30,000 | $70,000 | $150,000 |
| SharePoint Online site migration labour (30 TB) | $60,000 | $140,000 | $320,000 |
| Permission validation and remediation | $25,000 | $60,000 | $160,000 |
| FastTrack value (Microsoft-funded) | ($25,000) | ($45,000) | ($80,000) |
| End-user training and adoption support | $15,000 | $35,000 | $80,000 |
| Cutover support and hypercare (6 weeks) | $18,000 | $40,000 | $95,000 |
| Source file server decommission | $8,000 | $18,000 | $45,000 |
| Contingency at 15 percent | $33,000 | $73,000 | $180,000 |
| Net total estimate | $252,000 | $586,000 | $1,380,000 |
The typical-column number, $586K for 50 TB over 24 weeks, works out at roughly $11,700 per TB all-in. That is above the headline per-TB band for two reasons: the migration is split across two destinations (OneDrive and SharePoint) which adds coordination overhead, and the SharePoint Online site collection design adds labour that home folder migration to OneDrive does not need. For comparable home-folder-only migrations the per-TB cost typically lands at $4,000 to $6,000.
File share to OneDrive and SharePoint Online migration is well-tooled, well-funded by Microsoft, and structurally simpler than most other workload migrations. The cost discipline that produces an on-budget outcome is rigorous content discovery, aggressive retention policy application before migration, and deliberate permission model simplification at the destination. The teams that succeed treat the migration as an opportunity to retire content and simplify permissions, not as a verbatim lift of the source environment.
A. Mid-enterprise file share migrations of 10 to 50 TB typically cost $40,000 to $250,000 all-in including discovery, permission mapping, migration tooling, end-user communication, and source decommission. The per-TB cost ranges from $1,500 to $4,000 for straightforward home-folder migrations to $5,000 to $15,000 for complex departmental shares with deep permission inheritance.
A. Yes, the SharePoint Migration Tool (SPMT) from Microsoft is free for any customer with an eligible Microsoft 365 subscription. It supports migrations from SharePoint Server, file shares, network drives, and Google Drive. SPMT handles the data movement, basic permission mapping, and incremental updates. For migrations beyond about 10 TB or with complex permission scenarios, third-party tools usually save more in operational cost than they add in licensing.
A. Third-party migration tools typically charge per-mailbox or per-GB. AvePoint Fly typically lands at $4 to $12 per user-licence-month for the duration of the migration. BitTitan MigrationWiz typically charges $10 to $25 per user one-time. ShareGate Migrate typically charges per-user-licence on a perpetual or subscription model, with mid-market customers spending $15K to $80K on ShareGate licensing for a 12-month migration programme.
A. On-premise file shares use Windows ACLs (NTFS permissions) inherited from Active Directory groups. OneDrive and SharePoint Online use a different permission model (sharing permissions plus site-level access via Microsoft 365 groups or SharePoint groups). The mapping between the two is rarely one-to-one, and the migration process must decide how to translate each NTFS permission into a SharePoint or OneDrive equivalent. Permission mapping typically takes 20 to 40 percent of total migration labour.
A. OneDrive is for individual or small-team content (home folders, personal work-in-progress, draft documents). SharePoint Online is for departmental, project, and organisational content (shared resources, knowledge bases, collaborative documents). Most migrations split content: home folders to OneDrive, departmental shares to SharePoint Online or Teams. Microsoft Teams is technically built on SharePoint Online and is often the de facto destination for collaborative shares.
A. Small migrations under 5 TB complete in 4 to 12 weeks. Mid-enterprise migrations of 10 to 50 TB take 12 to 36 weeks. Large enterprise migrations of 100+ TB run 9 to 24 months. The timeline is rarely constrained by data movement speed (SPMT and third-party tools can sustain multi-TB per day throughput), but by permission mapping decisions, end-user readiness, and the decommissioning of source file servers.
Updated 2 May 2026