SharePoint tenant-to-tenant migration checklist

Before

1. Inventory the sites, libraries, OneDrive accounts and shares to migrate, with their volume and business owner.
2. Decide what stays behind: abandoned sites, archives, old versions beyond a threshold.
3. List what will need rebuilding: pages, web parts, workflows, Power Automate flows, apps.
4. Create the accounts and groups in the target tenant.
5. Build the identity mapping table and have it reviewed.
6. Create the target site collections and target OneDrive accounts.
7. Get admin consent for the application in each tenant.
8. Give the migration account site collection admin and term store admin rights.
9. Run the trial on a representative site, measure throughput and work out the total duration.
10. Announce the schedule to users: pass dates, cutover day, what changes for them.

During

1. Run the first full pass, outside business hours if possible.
2. Read the report: column warnings, unknown accounts, renamed files.
3. Fix the identity table or the target, then re-run incrementally.
4. Have business owners check a sample: versions, metadata, permissions.

Cutover day

1. Set the source sites to read-only.
2. Run the last incremental pass.
3. Compare the report counters with the inventory.
4. Open the target, share the new addresses, update bookmarks and important links.

After

1. Keep the source read-only for the agreed period, then archive or delete it.
2. Keep the state database and reports: they allow a catch-up pass and serve as a record.
3. Rebuild pages, workflows and flows.
4. Remove the application consent and the temporary admin access to OneDrive accounts.