Migrating to Google Workspace from Microsoft 365: Complete IT Admin Guide

Migrating from Microsoft 365 to Google Workspace is a significant project, but a very manageable one with the right plan. Organizations switch for many reasons: lower cost, a preference for browser-based real-time collaboration, Chromebook standardization, AI included in the plan price, or simpler administration.

This guide gives IT admins a practical, phase-by-phase plan covering the migration decision, inventory, tool selection, identity, email and calendar, files, Teams content, cutover, decommissioning, and the human side of the change.

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Before You Begin: The Migration Decision

Not every migration is justified. Before committing, check:

• Power-user dependencies: who depends on advanced Excel (VBA macros, Power Pivot, large models) or desktop Word features? Plan to keep a small number of Microsoft desktop licenses for them if needed.
• Line-of-business integrations: which applications rely on Outlook add-ins, Exchange Web Services, SharePoint workflows, or Teams apps?
• Identity: will Google become your identity provider, or will you keep Microsoft Entra ID or Okta and use SSO?
• Devices: Windows devices managed by Intune need a plan: Google endpoint management, keeping Intune, or a third-party MDM.
• Full cost comparison: compare total Microsoft spend (including Entra ID, Intune, Defender, Copilot) with the equivalent Workspace edition, plus migration and training effort.
• Training budget: plan several hours of training per knowledge worker. It’s the most underestimated cost.

If these checks clear, proceed with a structured plan.

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Migration Phases Overview

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Phase 1: Planning and Preparation

Inventory your Microsoft 365 environment

Document:

• Users, licenses, and mailbox sizes (including archive mailboxes)
• Shared mailboxes, distribution groups, Microsoft 365 groups, and mail-enabled security groups
• Room and equipment mailboxes
• OneDrive data volumes per user
• SharePoint sites, document libraries, and their permissions
• Teams teams, channels, chats, and files
• Mail flow rules, connectors, and third-party mail filtering
• Apps integrated with Exchange, SharePoint, or Entra ID

This inventory drives tool choice, timeline, and the target design in Google Workspace.

Set up Google Workspace

1. Choose the edition (Business Standard suits many organizations; Business Plus adds Vault and advanced endpoint management)
2. Add and verify your domain in the Admin console
3. Don’t change MX records yet: mail keeps flowing to Microsoft 365 during migration
4. Design the organizational unit structure and groups
5. Recreate rooms and resources in Google Calendar
6. Decide on identity (see below)

Identity: who signs users in?

Provision users in Google before migration, through your IdP’s Google Workspace connector, Google Cloud Directory Sync, or CSV upload. See our SSO guide.

Choose your migration tools

Google’s migration product matrix recommends tools by source and organization size:

Data import is Google’s self-guided migration tool in the Admin console. For Exchange Online it migrates email, calendars, and contacts, has no extra tool cost, and needs no Google Cloud infrastructure. A companion planning utility estimates timelines and batches users. Only a super admin can run migrations.

Google Workspace Migrate is designed for large migrations (1,001+ users) and complex file sources such as SharePoint on-premises, file shares, and Box. Its installation and configuration take more effort. Google’s migration product matrix says Workspace Migrate for Exchange Online, SharePoint Online, and OneDrive stops being available at the end of 2026. Google’s Workspace Migrate help pages say it is no longer available for Exchange Online starting October 2026, and that its SharePoint Online and OneDrive connectors no longer get updates or bug fixes, so use data import or advanced data import for those sources.

Third-party tools (for example CloudM or BitTitan MigrationWiz) are also widely used, especially when you want a managed service.

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Phase 2: Email, Calendar, and Contacts

Using data import for Exchange Online

1. In the Admin console, open the data import (data migration) page and choose Exchange Online as the source
2. Connect to Microsoft 365 with the required admin authorization
3. Map Microsoft 365 users to Google Workspace users
4. Start the migration for the pilot group
5. Let the initial migration copy historical mail, calendars, and contacts
6. Run delta migrations to pick up new items before and after cutover

Mail flow during migration

Until cutover, mail is delivered to Microsoft 365 and copied over by delta migrations. Some organizations set up dual delivery during the pilot so pilot users receive mail in both systems; our coexistence guide covers routing options.

Calendars and rooms

Calendar events and contacts migrate with mail. Recreate room and equipment resources in Google first, so room bookings can be mapped. Recurring meetings with complex patterns occasionally need cleanup; tell users to check their recurring meetings in the first week.

Shared mailboxes and groups

• Distribution groups → Google Groups
• Shared mailboxes → Google Groups with Collaborative Inbox, or delegated Gmail accounts
• Microsoft 365 groups → Google Groups plus a shared drive for files

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Phase 3: Files in OneDrive and SharePoint

OneDrive → My Drive

OneDrive content maps naturally to each user’s My Drive. Migrate it with data import (or a third-party tool) before cutover, then run a delta pass.

SharePoint → shared drives

SharePoint document libraries usually map to shared drives:

1. Design the target shared drive structure with each department. Don’t simply copy every SharePoint site
2. Create shared drives and add Google Groups as members
3. Map SharePoint groups to Google Groups
4. Migrate content and permissions, then review access

Very large or deeply nested libraries may need splitting: a shared drive holds up to 500,000 items, including files, folders, shortcuts, and items in trash.

Convert or keep Office formats?

Convert simple, collaborative files (meeting notes, trackers, presentations) so teams get real-time co-editing. Keep complex files (heavy macros, large financial models, intricate formatting) in Office format. Google Docs, Sheets, and Slides can open and edit Office files, so files can be converted later when they’re actively used.

Teams content

Decide what to do with Teams chats and channel conversations: migrate them with supported tools, export them for records, or start fresh in Google Chat with a read-only archive period. Files in Teams channels live in SharePoint and follow the SharePoint plan.

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Phase 4: Cutover

Cutover is the window when mail delivery switches from Microsoft 365 to Google Workspace.

Cutover checklist:

• Users trained and pilot feedback addressed
• Historical mail, calendars, contacts, and files pre-migrated
• SPF updated to include Google and DKIM set up for Gmail
• Groups, shared mailboxes, and rooms recreated and tested
• SSO and SAML apps tested
• Third-party apps that send mail reconfigured
• Mobile setup instructions ready
• Helpdesk briefed and staffed

Change the MX records

Google’s current MX record is a single entry:

Older Google Workspace accounts may use records beginning with aspmx; those remain supported. Remove Microsoft’s MX record so there’s only Google’s. Lower the TTL a day or two before cutover so the change takes effect faster, and allow up to 72 hours for it to be recognized everywhere.

During propagation, some mail may still arrive at Microsoft 365. Keep Microsoft 365 mailboxes active and run delta migrations until no new mail arrives there.

Email authentication

Update SPF to authorize Google, turn on DKIM in Gmail, and keep DMARC monitoring through the change so you can see any sender you missed. See our SPF, DKIM, and DMARC guide.

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Phase 5: Post-Migration and Decommissioning

• Run final delta migrations and check the migration reports for errors
• Keep Microsoft 365 licenses for a short safety period, then reduce them
• Export or retain any Microsoft data required by your records policy before deleting it
• Update third-party SaaS apps to use Google SSO
• Remove Microsoft MX, autodiscover, and other DNS records you no longer need
• Collect user feedback and fill training gaps
• Set up Vault retention (on editions that include it) so compliance coverage continues from day one

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User Training: The Make-or-Break Factor

The technical migration is the easier part. Adoption decides whether the project succeeds.

Suggested minimum per user:

• 30 minutes: Gmail essentials (labels, search, keyboard shortcuts, Outlook differences)
• 20 minutes: Google Calendar and Meet
• 30 minutes: Drive, shared drives, and real-time editing in Docs and Sheets
• Short recorded videos and a one-page “where did my X go?” guide

Champions (trained users in each department who help colleagues) reduce helpdesk load and speed up adoption. Run drop-in sessions during the first two weeks after each wave.

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Common Pitfalls

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Conclusion

A Google Workspace migration from Microsoft 365 takes three to six months for most organizations above a few hundred users. Done well, it simplifies administration, lowers cost, and improves real-time collaboration. The keys are a thorough inventory, the right tools for your size (data import for most, advanced data import for the largest), a phased wave approach, careful cutover, and real investment in training.

Never rush the cutover. A slow, careful migration beats a fast one that needs a rollback.

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Official Google documentation:

• Google Workspace migration product matrix
• Use the default data import method for Exchange Online
• Shared drive limits in Google Drive
• Set up MX records for Google Workspace

Related reading:

• Google Workspace and Microsoft 365 Coexistence: running both platforms during a migration window.
• Google Workspace Email Authentication: SPF, DKIM, DMARC: configure these before your MX cutover.
• Google Workspace Shared Drives: set up shared drives before migrating file content.
• Google Workspace Business Plans Comparison: choose the right plan before you start.
• Google Workspace vs Microsoft 365: if the decision to switch isn’t final yet.