Office 365 Tenant to Tenant Migration Simplified with Comprehensive Solution

Maarten ~ Modified: April 12th, 2024 ~ Microsoft Office 365 ~ 11 Minutes Reading

Summary: This write-up is designed for Office 365 admins, and users, who are seeking a comprehensive solution that can assist them with Office 365 tenant to tenant migration. Constantly this guide will be modernized to reflect the latest developments in Microsoft Office 365 suite and migration process. So, stay tuned.

Microsoft 365 is a competitive Office suite used by most businesses. And, these days, migrating data from one Office 365 tenant to another has become a more common business activity than ever. But, it’ll be easier for you to carry out a successful migration, if you know the right approach. So, this detailed post will guide you and cover everything you need to know about Office 365 tenant to tenant migration.

Office 365 tenant is typically associated with DNS domain names and acts as a central & isolated container for different subscriptions and licenses. 

However, in various unavoidable conditions(which will be discussed in the coming section), many companies have to undergo a tenant-to-tenant migration. And, frankly, the migration process is not as easy as it seems. So, many admins prefer to take professional help and work with an automated tool like Migrator Wizard Office 365 Migration to make the process smoother and trouble-free.

Let’s get started with the topic and discuss the complete Office 365 migration procedure. 

But first, let’s understand;

When There Is a Need to Perform Office 365 Tenant to Tenant Migration?

Condition 1. If you wish to change the tenant’s name

You know, choosing a Microsoft Office 365 tenant name is a one-time event. So, it’s extremely important to select the tenant’s name carefully. You can’t just simply update the tenant name. To change the tenant name, you have to create a new tenant & migrate the data from the previous tenant.

Condition 2. In the case of Microsoft 365 Tenant Region Change

When you create a tenant account, it automatically checks the external IP that generated the request and provisions in that particular region. And, Microsoft doesn’t provide a facility to change the tenant region. 

So, if you want to change the tenant region then the only option is to create a new tenant in the desired location and migrate data between the tenants.

Condition 3. In scenarios like mergers and acquisitions

To stay ahead in business or simply want to grow their businesses, many organizations merge or acquire another. Dealing with such M&A activity is quite challenging and the more challenging part is migrating data to Office 365 or merging tenants. 

Office 365 tenant-to-tenant migration is required in the above three scenarios. 

But, before performing the actual migration, there are some practical facts you need to consider.

Here are The Office 365 Migration Project Metrics You Should Know

Microsoft Office 365 migration from one tenant to another is itself a big project. And, every project balances a “triangle” i.e. Time, Money, and Scope. Given the fact, that you can’t change one without affecting one of the others.

So, as an IT admin, while planning the O365 migration, it’s your job to keep the whole triangle from falling apart.

To retain the quality of the Office 365 migration process, it’s important to,

  • Properly schedule the migration(specify the time duration for the project to complete)
  • Allocate sufficient budget(for migration tools and other resources)
  • Carefully define the migration scope(since it is difficult to change the scope of the project once decided)

Now, let’s come to the question, of how to migrate Office 365 mailbox data from one tenant to another.

Know The Various Stages of Office 365 Tenant to Tenant Migration

To execute an effective migration, it has to go through some important stages. Let’s discuss them in detail.

Stage 1. Planning

Planning is the key to every successful migration. Draw a clear roadmap, identify the key objectives, and accomplish a hassle-free migration. So, it’s advisable to plan at least two weeks before the migration.

Below are the points you should consider while planning.

  1. Prepare Tenant and Licensing
  • Accommodating all the mailboxes is crucial, so, it’s good to increase the destination Office 365 licenses.
  • Create admin accounts for Source & Destination beforehand to perform Office 365 tenant-to-tenant migration.
  1. Resource Creation at the Destination
  • You must create the objects from the source AD DS in the destination AD DS via consolidation If you use the Azure AD Connect tool to sync all objects from the destination Active Directory Domain Services(AD DS).
  • If any Rooms, Resources, Groups, or Users are managed in the O365 admin center of the source then you must create these objects at the destination. You can manually create through Windows PowerShell in-line commands.
  1. Communicate with End-user
  • You need to have clear communication with your staff about the upcoming migration. Notify all the users beforehand.
  • Also, make sure all users are aware of how to connect to Outlook on the web with their new sign-on information.

Stage 2. Preparation 

It’s necessary to prepare a checklist for pre-migration activities at least 3 days before you migrate.

The preparation checklist should include the following points;

  1. Prepare The Domain
  • You need to start the domain verification process on the target Office 365 for the source email domain.
  • Add the source domain and create TXT records in DNS(Domain Name Systems) for verification in the destination Office 365 admin enter. It may take up to 72 hours for the whole process to complete.
  1. Schedule Migration
  • Prepare a master list of Office 365 user mailboxes that you want to transfer.
  • Create a .csv file for mailbox mapping to match the source mailbox with the destination mailbox. Have a look at the below CSV file template.
  1. Schedule TTL Test

Then, perform the Mail exchanger record(MX record) time to live(TTL) test.

  • In DNS, change the TTL value on the MX record for the primary email domain that you want to migrate. Make it to the lowest value. 
  • Validate the MX and DNS changes through Mx Lookup.

Below is the screenshot of Mx Lookup.

  1. Disable Directory Sync

In the source Office 365 admin center, you need to disable the directory sync. Since the process takes 24 hr or more, it’s vital to ensure that the directory sync is disabled before migration. 

Once you deactivate, any changes made to the source AD DS will no longer sync further.

Stage 3. Migration 

Now, it’s the day of migration. Follow the below points to ensure a smooth migration.

  1. Stop Inbound Mail Flow
  • Make sure to change your primary MX record to a domain that is not reachable. By doing so, the internet servers trying to deliver a new mail will queue the mail and attempt redelivery after 24 hours. It may return a non-delivery report (NDR) to the user.
  • On the other hand, you can use an MX record backup service. Thereby, your emails will be queued for days or even weeks. And, when the migration process completes, the service will deliver the queued emails to your new Office 365 account.
  1. Prepare Source Tenant
  • It’s essential to remove the primary email domain including all the objects in the source tenant before the domain can be moved to the destination tenant.
    • If you had configured your domain with SharePoint Online public website then before migrating, you need to set the website’s URL back to its initial domain.
    • Remove Lync licenses(Lync Sip addresses connected to the source tenant) from the users in the Source tenant using the Lync admin portal.
    • Reset default Office 365 source email addresses. Change them to the initial domain i.e.
    • Remove all the proxy addresses from user objects that are still using the source domain.
  • Use the PowerShell command Get-MsolUser -DomainName to fetch a list of objects that are blocking removal.

It may take approximately an hour to remove the domain from the old tenant.

  1. Prepare Destination Tenant

After removing the domain from the source tenant, complete the authentication of the source domain in the destination tenant.

  • You need to configure auto-discover CNAME(internal/external).
  • If using AD FS, set up the new domain in the target for AD FS.
  • Start mailbox activation at the destination tenant and assign licenses to the destination user accounts.
  • Use Windows PowerShell to set the source email domain as the primary address for the new users.
  • Set passwords on all mailboxes in the target tenant. If you are not using a common password then you have to notify users about the new passwords.
  • After confirming that mailboxes are licensed & active, start the process of routing the mail. 
  • Verify the mail flow from/to new mailboxes at the target tenant.
  • Rebuild the mail flow rules in the destination tenant.
  1. Start Office 365 Tenant to Tenant Migration

After planning & preparation, it’s time to perform the migration. Take the help of the above-mentioned Tool and smoothly execute the migration.

When you use a professional tool, it not only lets you migrate unlimited emails but also reduces the risk of data loss during the migration.

Step By Steps Software Procedure for Office 365 Tenant-to-Tenant Migration

The migration steps include:

Step 1. Download the migration tool and launch it on your system.

Download Now Purchase Now

Step 2. Choose the source and destination as ‘Office 365’. Then move the workload selection area.


Step 3. Tick all the workload categories checkboxes. If you need a selective migration then you can enable a date filter for each of the mailbox categories. 


Step 4. Enter the Admin Email and Application ID for both Source and Destination to perform Office 365 tenant to tenant migration.


Step 5. Verify all the required source and destination permissions for the migration.


Step 6. Define users through various options i.e ‘Fetch Users’, ‘Import Users’, or ‘Download Template’


Step 7. Map the source and destination users and once again verify the permission.


Step 8. Select the required user accounts and see the priority for the migration. Finally, click on ‘Start Migration’ to migrate data between Microsoft 365 tenants.

Salient Features of The Tool:

  • Allows you to perform bulk migration.
  • You can apply a Date Filter to migrate only selective data.
  • It’s possible to execute account-based priority migration.
  • In case, some items are failed or are skipped during the initial run then it lets users perform a Re-run migration.
  • Also allows you to perform Distribution Group migration to Office 365

And, many more…

Stage 4. Finalize with Post Migration

It doesn’t end here. You need to perform a post-migration clean-up. Make sure to clear the Outlook Auto-Complete List.

Next, you need to ensure that all the source mailbox data along with crucial emails are safely migrated to the target tenant without any data loss. At last, you have to arrange training sessions(if necessary) to educate the staff about the new Office 365 environment.

Also Read: How to Move Office 365 Mailbox to Another User Account Safely?


Office 365 tenant-to-tenant migration process can be quite complicated if not done in the right way. So, it’s crucial for organizations to take extra care while planning an Office 365 migration checklist. To make things easier for the admins, this write-up explained all the steps, from planning to execution in a detailed manner for carrying out an error-free migration.


Q1. What are the challenges of tenant-to-tenant migration in Office 365?

Since Office 365 tenant-to-tenant migration is a big project to undertake, hence proper planning and execution are the biggest challenges of all time.  It requires careful planning and excellent execution to avoid any data loss or business downtime during or post-migration. 

However, some of the other challenges can be as follows:

  • Challenges in Data Mapping and Integrity
  • Potential Downtime and Disruption
  • Complexity of Workloads
  • Lack of Native Migration Tools
  • Regulatory Compliance and Governance
  • User Experience and Training
  • Post-Migration Testing and Validation
  • Costs and Resource Allocation

Overcoming all the above-listed challenges requires comprehensive planning and execution. However, by using the above-listed software users can overcome all the challenges without any technical expertise. 

Q2. How long does Office 365 tenant-to-tenant migration take?

The overall time for data migration especially in tenant-to-tenant migration depends upon several factors such as:

  • Amount of Data to be Migrated
  • Network Speed 
  • Migration Method 
  • Custom Configurations 
  • Licensing and Services 
  • Post Migration Cleanup & Configurations 

In general, a standard tenant-to-tenant migration can take anywhere from several days to a few weeks, depending on these factors. 

However, if you switch to the above-mentioned software then it can significantly reduce the overall time. Using the batch migration feature you can easily schedule multiple batches to speed up the conventional migration. 

Q3. What are the reasons – why people move to Office 365?

There are several reasons why users are moving to Office 365 from other email platforms, some of the note-worthy reasons are mentioned below. 

Microsoft Office 365 offers: 

  • Secure Cloud Accessibility
  • Scalability and Flexibility
  • Enhanced Collaboration
  • Updated Software
  • Cost Efficiency 
  • Help Fulfil Security and Compliance
  • Mobile Compatibility
  • AI-Driven Advanced Features

Microsoft offers cloud-based access to its productivity suite i.e. Microsoft 365  aka Office 365. It enables users to access their data from anywhere with an internet connection using any device. Furthermore, it enables great flexibility and improves overall collaboration. These features and offerings attract users to shift to Office 365 from other platforms to leverage its benefits.