Google Workspace to Microsoft 365 Migration

Move Gmail, Google Drive, calendars and collaboration into Microsoft 365 through a controlled, discovery-led migration.

Before recommending a migration method or providing a final implementation price, we establish what your organisation actually uses, what must move and how it should work in Microsoft 365.

Start with a Migration Readiness Assessment

A mailbox count alone is not enough to price or plan a reliable migration. We first establish the users, data, applications, domains and working practices that depend on Google Workspace.

What we assess

• Active, suspended, former and shared accounts.
• Gmail, calendars, contacts, aliases and forwarding.
• Personal Google Drives and Shared Drives.
• Google Groups and shared resources.
• Third-party applications and Google sign-in dependencies.
• AppSheet and other Google Workspace services.
• Domains, DNS, mail routing and authorised email senders.
• Retention, Google Vault and historic-data requirements.
• Proposed Microsoft 365, OneDrive and SharePoint destinations.

What you receive

• A documented source-environment inventory.
• Confirmed decisions and unresolved dependencies.
• A proposed Microsoft 365 destination design.
• A migration methodology and cutover approach.
• A defined implementation scope and cost.

Migration Readiness Assessment — from £750 + VAT

Implementation is priced separately once the users, data, applications and required destination structure have been confirmed.

What This Migration Covers

Assessment and design

• Environment inventory.
• Account classification.
• Data-volume assessment.
• Application-dependency review.
• Destination and identity mapping.
• Cutover planning.

Migration implementation

• Gmail, calendars and contacts to Exchange Online.
• Personal Drive data to OneDrive or agreed SharePoint locations.
• Shared Drives to agreed SharePoint sites.
• User, group and permission mapping.
• Domain and email cutover.
• Pilot migration, full migration and validation.

Separately scoped where required

• SharePoint restructuring and information architecture.
• AppSheet migration or redevelopment.
• Third-party application reconfiguration.
• Supplier liaison.
• Complex retention, Vault or legal-hold requirements.
• Large-scale device reconfiguration.
• Bespoke training.
• Extended post-migration support.

Migration software is only part of the project

Microsoft provides supported tools for moving Google mail and Drive data into Microsoft 365. We use the appropriate supported migration route for your environment rather than adding unnecessary third-party software costs.

The migration tool transfers supported data. It cannot decide which accounts are still required, where company information should live, which applications depend on Google, how SharePoint should be structured or how staff should work after migration.

A successful project combines the migration technology with discovery, design, testing, cutover control and user preparation.

1. Discover — Inventory users, data, services, applications and dependencies.
2. Decide — Confirm what moves, what is retired and where information belongs.
3. Design — Map identities, permissions, mailboxes, OneDrive and SharePoint.
4. Pilot — Test representative users, Gmail labels, file conversion and permissions.
5. Migrate — Run staged or controlled migrations and complete the domain cutover.
6. Validate — Check mail flow, data, permissions, applications and user access.

What may not move exactly as it works in Google

Google Workspace and Microsoft 365 organise email, files, permissions and collaboration differently. Some information can be transferred directly, while other elements require decisions, rebuilding or user preparation.

• Gmail labels may become Outlook folders.
• A message carrying several Gmail labels may appear in more than one folder.
• Shared calendars, room bookings and some calendar settings may need separate handling.
• Google Groups and collaborative inboxes need an agreed Microsoft 365 destination.
• Google-native files may require conversion and complex formatting should be tested.
• File ownership, permissions and sharing links need identity mapping.
• Applications using “Sign in with Google” may require account or authentication changes.
• AppSheet, scripts and workflows connected to Google data need separate assessment.
• Printers, scanners, websites and applications using Google for SMTP may need reconfiguration.

We test representative users and business-critical data before the main cutover so these differences are understood rather than discovered afterwards.

Clear decisions before migration

Your organisation confirms

• Which accounts, applications and services remain required.
• The business owner and purpose of required applications.
• What company data should move to SharePoint.
• Retention and legal requirements.
• The people authorised to approve DNS and cutover changes.

Altitude assesses and delivers

• The technical Google Workspace configuration.
• Permissions and migration dependencies.
• The supported migration route.
• Microsoft 365 destination mapping.
• Pilot, migration, cutover and validation.
• Separately priced remediation where additional work is identified.

Microsoft 365 Security Baseline Review · Microsoft 365 Tenant Ownership Review · Microsoft 365 backup

From the Blog

Moving from Gmail to Outlook may sound straightforward — but Google Workspace often contains far more than email. Learn what migrates, what needs redesigning, why discovery and security come first, and why Google should stay active until everything is validated.

Frequently Asked Questions

Can Altitude move Gmail to Microsoft 365?

Yes. Gmail, calendars and contacts can be migrated into Exchange Online using Microsoft's supported Google Workspace migration routes. The route is selected and managed after the source environment and requirements have been assessed.

How much does a Google Workspace migration cost?

The Migration Readiness Assessment starts from £750 + VAT. Implementation pricing depends on the confirmed number and type of accounts, data volume, Drive structure, applications, destinations and support requirements. We do not provide a misleading fixed implementation price based only on mailbox numbers.

Can we keep our existing email addresses?

Yes. Your email addresses belong to your business domain. The domain is verified in Microsoft 365 and mail routing is changed during the planned cutover.

Can Google Drive move to OneDrive?

Supported personal Drive content can move to OneDrive. Company or departmental information currently held in personal Drives may be better placed in SharePoint and must be mapped before migration.

Can Shared Drives move to SharePoint?

Yes. Supported Shared Drive content can move into agreed SharePoint sites. The destination structure, owners, groups and permissions should be designed before migration rather than copied without review.

What happens to Gmail labels?

Gmail labels and Outlook folders work differently. Labels may become folders, and messages with several labels can appear in several folders. We test representative mailboxes and agree how important labels should be handled.

Will applications using Google sign-in stop working?

They may require changes. We identify applications that depend on Google authentication or Google Workspace data. Your organisation confirms which applications remain required, after which we assess the migration impact. Detailed reconfiguration is separately scoped where necessary.

Can AppSheet applications continue after migration?

Possibly, but they require specific assessment. AppSheet applications may depend on Google accounts, Sheets, Drive folders, ownership and automations. These dependencies must be understood before changing or removing the originating Google accounts.

Will there be downtime?

Mail and data can normally be synchronised before the final cutover, reducing disruption. The precise cutover approach depends on the environment, domains, applications and migration route identified during assessment.

Do you carry out a pilot migration?

Yes. Representative users and business-critical data should be tested before the main migration. This helps identify Gmail-label behaviour, file-conversion issues, permission differences and application dependencies.

Can we retain Google Workspace temporarily?

Yes, where required. Some organisations retain selected Google accounts temporarily while data, applications or retention requirements are resolved. Any temporary coexistence arrangement is included in the migration design.

What happens to former-user data?

Former accounts must be classified before migration. Depending on business and retention requirements, their data may need to be migrated to a mailbox, archive, OneDrive, SharePoint or another approved location.

Plan the migration before moving the data

Start with a clear understanding of your users, data, applications and required Microsoft 365 structure. We will help you establish the scope before committing to the migration.

Migration Readiness Assessment from £750 + VAT.