Moving from Google Workspace to Microsoft 365 involves more than transferring mailboxes. A useful migration plan covers users, data, application dependencies, security, communication and the moment people start working in the destination environment.
Agree what is moving
Email and personal data
Inventory mailboxes, aliases, calendars and contacts. Microsoft’s Exchange migration tools support Google Workspace mail, calendars and contacts, subject to the chosen method and its documented limitations.
Files and shared content
Assess Google Drive, shared drives, ownership, permissions and Google-format files as a separate workstream. A mailbox migration should not be assumed to move these files or preserve every sharing behaviour.
Accounts and connected tools
List groups, delegated access, devices and applications using Google sign-in or mail services. Decide what must be reconfigured and who owns each change.
Prepare the destination and migration access
Select suitable Microsoft 365 plans and prepare the destination accounts. Confirm domain ownership, administrative access and the mail-routing design before making changes. Microsoft documents prerequisites in both the Google and Microsoft environments for its Exchange migration methods.
Give each migration task an owner and an agreed completion check. Keep credentials out of planning documents and contact forms; use an approved secure method when access is required.
Run a representative pilot
Select a small group covering different mailbox sizes, devices and working patterns. Test the migration method, access to mail and calendar data, aliases and the user sign-in experience. For files, test permissions, ownership and important document formats separately.
Record what transferred successfully, what needs remediation and what is outside the agreed scope. Use those findings to refine the rollout schedule and user instructions.
Plan the cutover and communications
Agree the migration batches, mail-routing changes, final synchronisation steps and the point when users should switch to Microsoft 365. Give staff clear instructions for signing in, configuring supported apps and reporting problems.
Microsoft’s migration documentation describes routing and batch-completion steps for switching users. The actual timetable depends on data volume, permissions, method, platform limits and business requirements. Avoid promising a fixed duration or zero disruption before assessment.
Validate before closing the source environment
Check incoming and outgoing mail, aliases, calendars, contacts and agreed file locations. Ask business owners to confirm that critical workflows work in the destination. Review security controls, access and device setup as part of the handover.
Agree source retention, recovery arrangements and retirement criteria before cancelling Google subscriptions or removing access. Keep the source available for the agreed validation period rather than treating the initial transfer as the end of the project.
Prepare your migration enquiry
- User and mailbox counts, approximate sizes and domains.
- Drive and shared-drive scope, ownership and permissions.
- Key applications, business dates and internal project contacts.
- Required Microsoft plans, security controls and support scope.
Explore Microsoft 365 migration support or read our Business plan-selection guide.