Office 365 Migration | 10 min read

Office 365 tenant to tenant migration with ShareGate Desktop

WRITTEN BY Sophie Falciglia
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How to combine Office 365 tenants after a merger of acquisition.

Updated on August 15, 2019.

You did it! You made the move to Office 365! You're ready to settle down and stay awhile—where could you possible move to from here, right?

One day your boss knocks on your door and says the company is merging domains following a recent acquisition. Luckily, the other company's intranet is also hosted in Office 365. But what happens next?

Preparing to merge tenants in Office 365

The thought of a second migration might be daunting—but there's no need for fear with ShareGate Desktop here!

Like any other migration, the first thing you should do is prepare accordingly. Our ultimate Office 365 migration checklist is an invaluable resource when it comes to avoiding costly mistakes and ensuring everything runs smoothly from start to finish.

Features in the ShareGate Desktop app can also help you stay on top of things:

  • Run the Inventory feature to build an inventory of everything in your SharePoint environment. Knowing exactly what you have—and where it's located—will help you assess what should and shouldn't be moved.
  • The Pre-check report lets you simulate your migration, so you can see and address potential issues without impacting your actual live environment.
The Inventory feature builds an inventory of everything in your SharePoint environment.
ShareGate Desktop's Inventory feature gives you visibility on everything in your SharePoint environment.

What to expect during migration

You already know ShareGate Desktop can seamlessly handle a SharePoint to SharePoint migration. But what should you expect when it comes to other Office 365 applications?

OneDrive for Business to OneDrive for Business

ShareGate Desktop can also help move your users' content from one OneDrive for Business to another. You can even use PowerShell to automate your OneDrive for Business to OneDrive for Business migration.

To complete a OneDrive for Business migration:

  1. Create a CSV guide for your migration by following the step-by-step guide in our ShareGate Desktop support documentation.
  2. Copy and paste the following script in the PowerShell application of your choice:
PowerShell script to automate migration.
Paste this script in whatever PowerShell application you prefer.

Note that:

Office 365 Groups content

Office 365 Groups provide a way to centralize membership for multiple Microsoft products in one place.

And because you can use Groups to apply policies to teams or departments, it's also key for implementing an effective cross-product governance strategy.

So what happens to groups when you're trying to merge tenants? Can they be moved from one Office 365 environment to another? They can—but it's not a seamless process.

We recommend that you:

  1. First identify all the groups at your source that you want to keep.
  2. Recreate those groups at your destination.
  3. Once that's done, ShareGate Desktop can migrate the SharePoint content from each group.

Ideally, you don't want to transfer permissions over with the content. That way you avoid any complications.

To get a better idea of what you're dealing with, list and identify your Office 365 Groups in our Explorer before migrating.

List and identify your Office 365 Groups in ShareGate Desktop's Explorer tab.
List and identify your Office 365 Groups in the Explorer tab.

What about speed?

There's no sugar coating it—moving between two Office 365 environments will be slower. Much slower.

When migrating from one Office 365 tenant to another, the biggest bottleneck is caused by the way we fetch structure and content information from your source tenant.

At this time, the migration API is only available when writing to a destination environment; all information extraction from your source has to go through the more traditional client-side object model.

ShareGate does have mechanisms in place to avoid being throttled by Office 365—but we still have to limit the number of simultaneous requests we send your source environment's CSOM to prevent additional slowdown. That's why an import from a file share, or a copy from on-prem to Office 365 is much faster than a copy between two Office 365 tenants.

Knowing all this, what can you do to avoid unnecessary grey hairs?

  • Migrate during off hours. This is your best chance to gain as much speed as possible.
  • Make sure your bandwidth is at its strongest. The operations are all done online, so having strong bandwidth is crucial.
  • Follow the tips in our curated guide. Download a copy of How to Optimize Your Migration Speed When Using ShareGate to learn how ShareGate interacts with the different components of your migration—as well as what bottlenecks to look out for that could negatively impact its speed.

When everything is finished, run a migration report to make sure everything was transferred over to your destination.

Stay alert and keep your content secured

You've made the move to Office 365 once again—the merger was a success, and so was your migration. Great!

But in order to take full advantage of new Office 365 concepts—including Office 365 Groups, Microsoft Teams, and modern group-connected team sites—you need to go one step further.

After migrating from on-premises to online, you now need to make the transformation to what Microsoft has dubbed the modern workplace.

In our webinar, You made the move to Office 365—now what?, Microsoft MVP Benjamin Niaulin explains how to leverage your Office 365 subscriptions to keep pace with the modern workplace. Check out the recording, download the slides, or read a recap of his key points.


Making the move to modern doesn't have to be complex.

At ShareGate, we want to help you evolve as fast as the technology the cloud provides.