A SharePoint migration is not a simple file copy; it is a strategic relocation of your organisation’s digital headquarters. Whether you are on an aging end of support on-premise SharePoint Server or a third-party solution, having a structured migration plan is a critical requirement for success.

This 2026 SharePoint Migration Plan provides a comprehensive roadmap for moving from legacy on-premises servers (or outdated cloud structures) to a modern, secure SharePoint Online environment.

5-Step SharePoint Migration Plan

Phase 1: Audit your existing setup

Before moving a single file, you must understand what you have. Moving old out of date data that no one needs into a modern cloud environment will only replicate old problems.

Spending time to catalogue all sites, libraries and workflows. Depending on the state of your environment this can be a significant effort. There are tools available that can assist this.

You also want to audit all of your customisation’s things like workflows, infopath forms and custom solutions will all need to be identified and rethought as part of the migration.

Phase 2: Information Architecture & Governance

The biggest mistake in migration is “lifting and shifting” a 10-year-old folder structure. Modern SharePoint requires a “Flat Architecture.” Applying a new architecture that supports search and the modern approach to data structure is key. But at this stage also starting to put good governance in place is key.

3 actions to consider:

  • Move to Hub Sites: Replace deep subsite hierarchies with flat site collections associated with Hub Sites. This improves searchability and security management.
  • Define Metadata Strategy: Shift from deep folder nesting to metadata tagging. This allows users to filter by “Department,” “Project,” or “Document Type” instantly.
  • Apply Zero-Trust Security: Map legacy permissions to Microsoft Entra ID (formerly Azure AD) groups. Ensure sensitivity labels are ready to protect confidential data automatically.

Phase 3:  Migration Approach

Once you have understood your data you need to design your actual migration approach, do you use a SharePoint Migration Partner, or run the migration yourself using one of the SharePoint Migration tools.

Pre-provision the SharePoint sites and OneDrive accounts in the cloud. Ensure your UK network bandwidth can handle the massive data upload without throttling.

Phase 4: A Phased Migration

How you roll this out and carry out your migration is critical for success. The best approach is to split this up into waves and run a pilot first to ensure your migration process works.

  1. Pilot Migration: Select a non-critical department (e.g., Marketing) to migrate first. This tests the migration speed, permission mapping, and link integrity.
  2. User Acceptance Testing (UAT): Have department “Champions” verify their data. Checklist: Are the files there? Do permissions work? Can they co-author documents?
  3. Wave 1, 2, 3…: Group the remaining departments by complexity. Execute migrations over weekends to minimise business disruption.

Phase 5: Post-Migration & Adoption

A migration is only successful if your employees actually use the new system.

  • Decommission Legacy Servers: Once a wave is validated, set the source data to Read-Only to prevent “version drift,” then decommission the old servers after 30 days.
  • Staff Training: Provide short, role-based training videos. Focus on “What’s Changed” -specifically how to use search and Teams integration instead of hunting through folders.
  • Automated Governance: Use Microsoft Purview to apply retention policies so your new environment doesn’t become cluttered again by 2027.

A SharePoint migration when managed correctly can be a great project that vastly improves your productivity, collaboration and document management. When mismanaged you can lose data, lift and shift old data that disenfranchise users. Our 5-step approach is built on our proven methodology and years of experience migrating files and document management solutions to SharePoint Online. Discover our SharePoint Migration Services or contact us today.