Office 365 is one of the most popular cloud-based SaaS productivity suites that has transformed the way people work and collaborate. Even though it offers excellent features, such as email, file storage, and sharing, there are still situations where organizations may need to migrate their data from one tenant to another. This is particularly true for mergers and acquisitions when two companies merge with different IT infrastructures. This process is known as Office 365 Tenant to Tenant Migration or Cross-Tenant Migration.
There are several cloud email migration services available in the market that can help you migrate your data seamlessly from one Microsoft 365 tenant (formerly known as Office 365) to another. However, if you’re looking for a manual procedure to perform this migration, this article will guide you through each step of the process.
Step-by-Step Guide: Office 365 Tenant to Tenant Migration
Let me mention some prerequisites that one should keep handy before diving into manual tenant-to-tenant migration such as Global Admin access rights credentials of both old (source )and new tenants, DNS credentials, and knowledge of PowerShell scripts.
Before we proceed with the essential steps of the migration process let us understand some basic terminologies used in O365:
Source Tenant – The source tenant is defined as an existing or old office subscription.
Destination Tenant – The destination/ target tenant refers to a new or already created O365 subscription where you want your migrated data.
Admin account – An admin account is defined as someone who has authorization/authentication access rights for both source and destination tenants.
Now let’s dive into our step-by-step guide:
Prepare Source and Target Tenant
First you need to prepare Source and Target Tenant. This requires performing some tasks like app registration and creating mail enabled security group.
Create Mail Users
Create mail users in destination tenant for whom you want to migrate data from Source sight. Do not apply license to mail users.
Use PowerShell to Perform Some Tasks
Once you had done with the above steps, you need to create organization relationship and migration endpoint in the source tenant.
After that you need to accept the organization relationship in the target tenant to create the relationship between source and target tenant.
After that you need to add ExchangeGUID and LegacyExchangeDN of the source tenant in the target tenant.
Apply Licenses
Now apply licenses to all the mail users you had created earlier. Once you apply the licenses, it will create the mailboxes for all the mail users and convert them to regular users.
Test Migration Server
Verify that everything you had done is correct by running a PowerShell Command in destination tenant. If the result will be success, you are good to go. But if it will show failed, you need to check what you had missed.
Add Migration Batch
Once all above steps are performed, you need to create migration batch through Office 365 Exchange Admin Center. It is the last step for completing mailbox data transfer from one tenant to another
To read all these steps in detail visit this article on Tenant to Tenant Migration.
Conclusion:
Overall, if you’re well-prepared and follow this step-by-step guide properly, a manual Office 365 tenant-to-tenant migration can be performed smoothly without any issues. I suggest you to use third party migration service if you are looking to migrate large number of users. I hope this guide has helped you in migrating data between Office 365 tenants.
Read More: Migrate from Google Workspace to Office 365