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tenant-to-tenant M365 migrationS

Effective tenant-to-tenant migrations: the ultimate playbook 

Whether you’re going through a merger, an acquisition, or a reorganization, this playbook will give you the insights you need to plan and execute your tenant-to-tenant Microsoft 365 migration efficiently.


Tenant-to-tenant migrations step by step—from the pros

With the increase of remote collaboration through Microsoft 365 tools, tenant-to-tenant migrations have had an upswing in recent years. They’re also a reality in a dynamic business world where mergers, acquisitions, divestitures, and reorganizations are commonplace.

Read on for the answers to some of the most common questions about tenant-to-tenant migrations. For industry insights and more in-depth info, grab a copy of our ultimate playbook created for savvy IT admins.

What’s in this playbook

  1. Understanding tenant-to-tenant migrations
  2. Planning your migration
  3. Executing your migration 
  4. After your migration

Understanding tenant migrations in Microsoft 365

Understanding 3

What is a tenant-to-tenant migration?

It’s self-evident, actually. It’s when you migrate between office 365 tenants, either moving from one to another (or to multiple tenants), splitting a tenant, or bringing two of them together.

When does a tenant-to-tenant migration happen?

There are four basic scenarios when you need a tenant-to-tenant migration:

  • Business mergers
  • Business acquisitions
  • Divestitures
  • Business reorganization


If you’re going through the trouble of migrating something from Tenant A to Tenant B, ensure everything gets to the destination with all of its access and permissions intact.

So, to make sure your tenant-to-tenant migration runs smoothly, take the time to identify and fix potential issues before you get started. It will minimize the downtime and potential impact on your users, reduce risk, and make your new Microsoft 365 tenant much easier to manage and secure.

Planning your migration process

Planning 1

What are the main risks while running a data transfer?

The main message here is: don’t underestimate your planning phase. According to a McKinsey study, around US$100 billion is expected to be wasted in unsuccessful migrations by companies worldwide in the next 3 years.

Here are some of the main risks to consider before your Microsoft 365 migration process:

  • Business discontinuity – Be proactive and plan your tenant-to-tenant migration so that content and workspaces are always available and functioning for everyone else.
  • Productivity loss – Users should be able to access their files and documents right after your tenant-to-tenant migration, so make sure to include this in your planning. 
  • Sprawl – If you don’t plan your target tenant’s structure well, you risk having a cluttered environment, making it much harder for people to find what they need to do their jobs.

Many IT organizations are stuck in a reactive mode, checking “what’s on fire,” but some realize they need to move forward and get things more predictable and manageable, with more self-service.


Marc D. Anderson

Microsoft MVP, Co-Founder and President of Sympraxis Consulting

How can I determine the time my migration will take?

There’s a plethora of factors that can impact migration time estimates. These are some of the main factors you should consider:

  • Structure complexity
  • Custom permissions
  • Metadata complexity
  • Number of versions
  • Large lists and libraries
  • Number of user accounts and admin accounts

The best way to establish an approximate migration time is to run a test migration within your source environment. It will also help you determine what kind of challenges you might face and establish a more realistic tenant-to-tenant migration plan.

Click here for more details about running a test and also for a full list of subjects that can affect your migration and update your tenants

Pro tip #2: organize and update your tenants

With a tidy environment, users are able to find what they’re looking for, wasting no time. It also makes your life a lot easier when you’re trying to decide which resources to migrate.

Finally, by staying on top of group ownership and external sharing links, you’ll be one step ahead when it comes to securing your data. So, don’t forget to have both the source tenant and the target tenant organized, updated, and cleaned up as part of your pre-migration planning.

ShareGate makes it much easier for you to clean up your source tenant and your destination environment. With the Quick actions menu, you can bulk edit content, modify the content of a list or library, download content to a local or shared drive, and much more.

Click here to learn more about it from our ShareGate documentation.

Executing your tenant-to-tenant migration

Executing 1

How can I ensure I’m migrating the right content?

A Microsoft 365 migration is a perfect opportunity to take stock of all content in your source tenant. By making a detailed inventory, you might find content that’s either duplicate, outdated, or no longer valid so that it can be archived and deleted before you transfer data unnecessarily to the target tenant.

An inventory of your source tenant is crucial to your migration process. It helps you make more informed decisions and estimate the required migration effort correctly.

How should I manage everyone else’s expectations?

Training and communication are essential to your Microsoft 365 tenant-to-tenant migration. Before and during the migration process, everyone must be on the same page about what to expect while the work is done.

Also, you should inform end users of the benefits of this move. After the migration, providing training and support will be key to driving adoption of the new tools.

If you want to learn more, check out this article about managing your end users during a Microsoft Teams migration. 

It’s not just the implementation, which is a beast on its own. It’s also educating your users on how to use things properly.


— Maarten Eeekels

Microsoft MVP, Microsoft Regional Director, and CTO of Rapid Circle

Okay, I’m ready to migrate. Where should I start?

Well, we won’t go into detail about it here. However, you’ll be glad to know we have many resources to help you each step of the way. Also, you should definitely consider third-party migration tools such as ShareGate to make the job. Otherwise, you’ll be facing a very complex process.

One of them, of course, is our ultimate Microsoft 365 tenant-to-tenant migration playbook, which you can download at the top of this page.

Here are some of the other resources we have available to help in your tenant-to-tenant migration process:

After your tenant-to-tenant migration

After 2

How can I validate that I had a successful migration project?

There are a few steps you can take to validate that your migration was successful: (Click here to check all details about these steps.)

  • Browse and verify your destination environments to make sure everything is in place
  • Ask users to validate that their content and data migration was done properly
  • Just in case, keep the source tenant for a few months after your migration
  • Look out for discrepancies between your tenants, like the number of items or their size
  • Establish a governance plan to ensure your target tenant remains secure and uncluttered

How can I take action to manage my target tenant?

The first step you should take is gaining visibility on your target tenant. Set up a reporting routine to be on top of your new tenant, and from the insights you get, you can manage permissions, check user activity, verify inactive teams, and make sure people are using the tools correctly.

ShareGate provides you with actionable custom reports so you can have full visibility of your tenants and take action immediately. Check our full list of reports and explore our Microsoft 365 reporting guide to know all your options, including out-of-the-box Microsoft reports.

ShareGate’s migration and management tools with a centralized inventory of SharePoint and Teams environments.
ShareGate’s migration and management tools with a centralized inventory of SharePoint and Teams environments.

ShareGate: migrating tenants with full efficiency

Sharegate 1

ShareGate is the go-to third-party tool for your tenant-to-tenant Microsoft 365 migration. You’ll love to merge, restructure, move, or ‘split and peel’ your Microsoft Teams and SharePoint environments with a simple drag and drop.

Here’s just a taste of what ShareGate can do before, during, and after you migrate:

  • Maintain data integrity – Migrate all kinds of content, including its metadata, with version history intact.
  • Leave no team, channel, or chat behind – Move channels, content, or entire teams in just a few clicks—while the whole team talks. 
  • Inventory your SharePoint – Start with our source analysis report for a high-level view, and then dig into the details.
  • Shape the new environment your way – Map permissions, flatten the folder hierarchy, and replace illegal characters: you’re in control.
  • Full visibility with actionable reports – Run our actionable, pre-built custom reports to give you full post-migration visibility. 
  • Migrate while people work – With the “copy if newer” feature, you avoid overwriting files at the destination tenant.
  • Empower your end users – Users create teams from the templates you provide them with, with your guardrails in place.

Our favorite thing: saving time for clients

The effort would quadruple if we had to do everything manually…. it almost couldn’t be done without ShareGate.


— Doug Punchak

Application Development Manager, Avvenire Solutions

Ensure business continuity during your migration with our insights