When one company acquires another, someone soon asks: "How do we move Copilot from their tenant into ours?" The short answer: there's no single button. Copilot moves in three separate pieces, and each one has its own path.
The three pieces at a glance
| What | How it moves | What to know |
|---|---|---|
| People and their content (mail, OneDrive, Teams chats and meetings) | Microsoft 365 Migration Orchestrator (or the cross-tenant mailbox and OneDrive tools) | It moves content, not identities. You create and license the users in the target tenant first, then map identities. It needs the per-user Cross-Tenant User Data Migration add-on. Mailboxes on hold are blocked from moving. |
| Copilot memory and personalization (saved memories, chat-history details, custom instructions) | No documented migration path. Plan as if it doesn't move. | Memories are stored in a hidden folder in the user's Exchange mailbox, and a cross-tenant mailbox move carries user-visible content (mail, contacts, calendar, tasks, notes). Users can export their custom instructions themselves under Settings > Personalization. Test with pilot users. |
| Copilot Studio agents | Solutions: export from the source environment, import into the target tenant's environment | Not everything carries over. Reconnect connections, re-set authentication, re-publish and re-share. |
| Agent Builder agents, Power Automate flows, Power Apps | Rebuild, or export and import as solutions where supported | The Microsoft 365 migration tools don't cover Power Platform. Connections and connection references must be rebuilt. |
Step by step
- Inventory the source tenant. Copilot-licensed users; Copilot Studio environments and agents (note each agent's harness); Agent Builder agents, flows and connectors; and any holds on mailboxes and OneDrive. Holds block migration and are usually the critical path.
- Identity first. Create and license the users in the target tenant, decide the UPN and domain plan, and run cross-tenant identity mapping.
- Move user content with Migration Orchestrator. Run mailboxes, OneDrive, Teams chats and meetings together in the same batch, and set a CompleteAfterDate for when users will feel the cutover.
- Tell users what won't follow them. Before cutover, users export their custom instructions and note any saved memories they rely on. Copilot rebuilds chat-history context over time in the new tenant.
- Move Copilot Studio agents with solutions.
- Put each agent in an unmanaged solution and choose "Add required objects" so topics, flows and environment variables come along.
- If the agent uses custom connectors, import those first, then the agent solution.
- Export, then import into a target environment (use a Managed Environment).
- After import, reconfigure user authentication, re-create connections, and check that knowledge sources and channels came across (the icon and channel details may be empty). Then publish and share.
- Rebuild what solutions don't carry. That includes Agent Builder agents, personal flows, and any knowledge source that points to the old tenant's SharePoint. Re-point it to the migrated sites.
- Re-set governance in the target tenant. Copilot Studio capacity and Copilot Credits allocation per environment, agent-level limits and spending alerts, and DLP policies and sharing rules.
- Pilot, then cut over in waves. Test 5–10 users end to end: mail, files, Copilot answers and the agents they use.