Office 365 Tenant To Tenant Migration Same Domain Process Explained

How Office 365 tenant to tenant migration same domain ensures that users continue to use their existing accounts after the reconstruction process.

Tenant Migration Service Details

Click Above to Learn About Our 100% Done-For-You Tenant Migration Service. Migrate unlimited mailboxes for a flat fee of $295/-

When an organization goes through a merger or acquisition or has decided to rebrand or divest the business, the migration of critical organizational data such as mailboxes, email accounts, cloud storage accounts, and domains from one tenant to another is inevitable. According to Statista, over a million companies use Microsoft Office 365 as of June 2021; hence, an Office 365 tenant to tenant migration same domain is warranted sooner or later as most of these companies will grow through one way or another. An Office 365 migration service can come in handy in such situations, as there is no in-built option for source-tenant to target-tenant migration available today.

Table of Contents

Number of Office 365 company users worldwide as of June 2021, by leading country
Graph source: Statista

How Is Office 365 Tenant To Tenant Migration Same Domain Done?

Tenant to tenant migration in Office 365 involves multiple steps. However, it can be classified into two primary stages, the pre-migration, and the migration stages, as described below.

The Pre-Migration Stage

The activities comprising the pre-migration stage can be divided into four sub-stages, as follows.

Preparing The Domain

One needs sufficient space in the target tenant’s Office 365 to ensure successful data migration from the source. Additional licenses might also be required.
Opening administrator accounts is essential in both the tenants. It could require special tools to create multiple admin accounts.
Creating users, resource mailboxes, and distribution groups are also essential.
ADDS (Active Directory Domain Services) tools might be necessary for performing active directory domain consolidation.
Synchronizing the source and target tenant is the next step.
Finally, training end-users on how to use Office 365 is necessary.

Verifying The Domain

The above step is followed by the process of verifying the target domain in Office 365.
It requires adding a source domain in the target Office 365’s admin center. Besides, creating TXT records in DNS is necessary.

However, the domain should be in use for one target tenant alone. Otherwise, the process would fail. The change would take around 72 hours to take effect.

Migration Scheduling

Generate a user mailbox list for migration and create a CSV file for mapping.
Note the minimum value of TTL on the MX record of the primary email domain.
Disable directory syncing for the source tenant.

Facilitate The Migration

Changing the primary MX record to an unreachable value stops the flow of inbound emails to the source tenant.
Next, it is essential to erase everything from the primary mail domain in the source tenant before migrating Office 365 to Office 365 alternative account.
Prepare the target domain by verifying the source tenant in the target domain. It should be one hour after performing the above transactions.
When using ADFS (Active Directory Federation Services), it is essential to configure a new domain for the target tenant for ADFS.
Activate new users in the target domain and assign new licenses.
The new users’ primary email address must be the source domain. It is also essential to share their passwords with them.

Now the pre-migration process for Office 365 tenant to tenant migration same domain is over. One can now use Office 365 tenant to tenant migration tools or PowerShell scripts.

The Migration Process

One can choose from two migration methods, depending on the number of users, as follows.

For up to 500 users, assigning a cut-off date can limit the volume of data migrated.
For more than 500 users, it is advisable to adopt a multi-pass approach.

One can migrate in stages. It allows users to start functioning while data migration continues in the background.

One difference to note when migrating to the same domain is that one must alter the user addresses to use the ‘onmicrosoft.com‘ domain on both servers, i.e., source and destination. When adding the domain to the destination tenant, there could be a minor delay as Microsoft only allows a domain to exist with one tenant at a time.

Migration Using The Office 365 Tenant To Tenant Migration Tool

Using specialized Office 365 tenant-to-tenant migration tools can help you expedite the migration process. It helps do the following.

Transfer Office 365 Subscription to Another Tenant

For hassle-free transfer of one tenant’s subscription to another, follow the below tenant to tenant migration Office 365 steps.

Purchase an individual plan.
Remove the custom domain present in the existing Office 365 account.
Set up a custom domain in the new subscription plan.
Cancel the existing subscription.

Merge Office 365 Tenants

Install Office 365 merger tool and log in to the system using the first Office 365 user account.
Add the second user.
On selecting the Import CSV option, one can import the corresponding CSV file.
Choose the CSV file location for combining multiple accounts and complete choosing all accounts that require merging.
Users are free to apply filters and grant the necessary permissions.
Select the Import CSV option and use the date filter option to specify the interval and decide the data volume to be exported.
Choose the Export option for merging the accounts.

Transferring Office 365 Mailbox Account to Another Account

It requires recreating the Outlook profile, procuring third-party licenses, and creating more administrative accounts.
Sync new users with the target tenant and train users in using the Outlook web version to prevent mistakes.
Add the domain to the target tenant and prepare the list of mailboxes to migrate.
Perform a TTL test and stop source tenant syncing.
Temporarily disable new incoming emails.
Verify source tenant and new mailboxes at the target tenant.
Complete the migration process.

Tenant to Tenant Migration OneDrive

Generally, Office 365 users avail of One Drive services for storage. However, tenant to tenant migration Office 365 One Drive is a complex process that requires a migration engine for a smooth transfer.

Create a source connector.
Configure the source, followed by the creation of a target connector.
Configure the target and create users.
Proceed with the migration.

Final Words

An organization going through a merger or acquisition may require Office 365 tenant to tenant migration same domain if Microsoft Office 365 is their primary business suite. The key advantage of performing the migration is that it lets employees use their existing accounts even after the organization’s reconstruction. What’s more, using Office 365 tenant to tenant migration tool makes it easy to migrate Office 365 to Office 365. If all the steps mentioned above in this article seem too cumbersome for you, then you can always consult an outside tenant-to-tenant migration expert who can make this entire process hassle-free for your organization.