Office 365 Tenant to Tenant Migration: A Detailed Guide

Migrating data from one tenant to another tenant is known as Office 365 tenant to tenant migration and is necessary for businesses undergoing mergers, acquisitions, divestitures, or rebranding. Basically, this process involves moving mailboxes, OneDrive files, SharePoint sites, and Microsoft Teams data from one Microsoft 365 environment to another.

When I first looked into this, I found that there are two main ways to approach it: manual migration and automated migration solutions. While manual migration can work for small-scale transfers, it has limitations. Automated migration, on the other hand, ensures a seamless and safe transfer. In this guide, I am going to talk about both methods and explain the best approach for different scenarios.

Scenarios for Office 365 Tenant to Tenant Migration

Before proceeding with the migration process, it’s important to understand why a business might need to migrate its Office 365 data to another tenant. Here are some common scenarios:

• Mergers & Acquisitions: When two companies merge, their Office 365 environments need to be consolidated into one tenant.
• Divestitures & Spin-offs: If a company sells a portion of its business or creates a new entity, a number of users may need to be migrated to a separate tenant.
• Rebranding & Domain Change: If a company changes its brand name and domain, migrating to a new Office 365 tenant with a new domain may be necessary.
• Regulatory & Compliance Requirements: Some industries and businesses may need to move data due to compliance or regulatory mandates.

Ways to perform Office 365 Tenant Migration

Now that we understand the scenarios, let’s look at the two main ways to migrate: manual and automated migration.

Manual Migration Process

What Can Be Migrated Manually?

The manual approach is best suited for small-scale migrations and is only capable of handling:

• Mailboxes (Emails, Contacts, and Calendar Items)
• OneDrive for Business Files

However, if you want to migrate SharePoint sites or Teams data, manual migration won’t be enough.

How to Migrate Mailboxes Manually

Microsoft provides a feature called Cross-Tenant User Data Migration, which requires an additional license known as the Cross-Tenant User Data Migration License. This allows IT administrators to move mailboxes between Office 365 tenants.

For a detailed guide on how to manually migrate mailboxes, you can check out this step-by-step tutorial: Office 365 Tenant Mailbox Migration

Limitations of Manual Migration

While manual migration can work, there are several limitations:

• Limited Scope: It only covers mailboxes and OneDrive files, leaving out SharePoint and Teams.
• Time-Consuming: The process requires technical expertise and can take a long time.
• Risk of Data Loss: Any misconfiguration can lead to missing or incomplete data.
• Disruptions to Users: Downtime can impact business operations and productivity.

Because of these limitations, most businesses opt for an automated migration solution instead.

Automated Migration: A Better Alternative

If you want a hassle-free and efficient migration, using an Office 365 Tenant to Tenant Migration Service is the way to go. These services cover:

✔ Mailboxes – Emails, Contacts, Calendar Events
✔ OneDrive for Business – User files and folders
✔ SharePoint Online – Sites, documents, and permissions
✔ Microsoft Teams – Chats, channels, conversations, and files

Benefits of Automated Migration

• Minimal Downtime: Ensures that employees can continue working without interruptions.
• Complete Data Transfer: Supports all types of data, including Teams and SharePoint.
• Faster Migration: Saves time compared to manual migration.
• Secure & Reliable: Reduces the risk of data loss or corruption.
• Audit Logs & Tracking: Allows IT teams to monitor the migration process.

Popular Automated Migration Tools

If you’re considering an automated migration, there are several tools and services available:

• Microsoft’s Cross-Tenant Mailbox Migration (for mailboxes only)
• CloudBik’s Migration (reliable migration services and affordable)
• BitTitan MigrationWiz (for full migrations but very costly)
• Quest On Demand Migration (popular but costly)

These tools make the migration process smoother and reduce the workload on IT teams.

Conclusion

Migrating Office 365 from one tenant to another is a necessary step for businesses undergoing structural changes. While manual migration can work for small-scale transfers, it is limited to mailboxes and OneDrive files and comes with risks. For a seamless and secure migration, automated migration services are the best option. If you're planning a migration, I highly recommend evaluating your needs and choosing the right method.