The basic process depends on which version you own

Moving Microsoft Office to a new computer is straightforward if you own a perpetual license (Office 2019, Office 2021, or older versions you bought outright), but it works differently if you have a Microsoft 365 subscription. With a perpetual license, you uninstall from the old computer, then install and activate on the new one using the same product key. With Microsoft 365, you simply sign in on the new computer and install from your account — the subscription follows you, not the device.

The method also depends on whether you still have access to the old computer. If you do, you can deactivate Office there before moving it, which is cleaner. If you don't — the old computer is broken, lost, or you no longer have it — you can still move your license, but you'll need to handle deactivation differently.

Key Takeaways

  • Microsoft 365 subscriptions move automatically when you sign in on a new computer; perpetual licenses (Office 2019, Office 2021) require you to uninstall from the old machine and reinstall using your product key.
  • You can install Office on up to five devices at once with Microsoft 365, but only one person can use the account at a time.
  • If you no longer have the old computer, sign into your Microsoft account on the new one, then contact Microsoft support to deactivate the old installation remotely.
  • Your product key for a perpetual license is found in your Microsoft account, in the original email receipt, or in the Office app itself under Account settings.
  • Office will not work on the new computer until you activate it, which requires an internet connection and a valid license.

Moving a Microsoft 365 subscription

If you pay a monthly or yearly fee for Microsoft 365 (formerly Office 365), your license is tied to your Microsoft account, not to a specific computer. Install Office on the new computer, sign in with the same Microsoft account you used on the old one, and you're done. The subscription automatically moves with you.

Download Office from office.com, sign in, and select Install. Choose whether you want the 32-bit or 64-bit version — 64-bit is standard for most modern computers. After installation completes, open any Office app (Word, Excel, Outlook), and you'll be prompted to sign in. Use the same email and password as your old computer. Once you sign in, Office activates automatically.

You can install Microsoft 365 on up to five devices at the same time, but only one person can use the account simultaneously. If you had Office on a work computer and a personal computer, you can keep both active. If you're replacing an old personal computer entirely, you don't need to do anything on the old machine — just install and sign in on the new one.

Moving a perpetual license (Office 2019, 2021, or older)

A perpetual license is a one-time purchase that doesn't expire. You own a product key that ties the license to your Microsoft account. To move it to a new computer, you need that product key, and you should uninstall Office from the old computer first.

On the old computer, open any Office app and go to File > Account. Look for "Product Key" or "About" — the product key appears as a 25-character code. Write it down or take a screenshot. Then uninstall Office: go to Settings > Apps > Apps & features, find Microsoft Office, and select Uninstall. Follow the prompts to remove it completely.

On the new computer, download Office from office.com or use installation media if you have it. During installation, you'll be asked to enter your product key. Paste or type the 25-character code. Sign in with your Microsoft account (the one linked to your license), and Office activates. If activation fails, restart the computer and try again — sometimes it takes a moment for the activation servers to recognize the key.

If you don't have access to the old computer

If the old computer is broken, lost, or you no longer have it, you can still move your license. The process is different depending on whether you have a Microsoft 365 subscription or a perpetual license.

For Microsoft 365, simply sign into your account on the new computer and install Office. Your subscription is not locked to the old device, so there's no deactivation step needed. However, if the old computer is still powered on and signed into your account, Office may show a warning that you're signed in elsewhere. This is normal and doesn't prevent you from using Office on the new machine.

For a perpetual license, sign into your Microsoft account on the new computer at account.microsoft.com. Go to Devices, find the old computer in your list, and select Remove. This deactivates the license on that machine. Then install Office on the new computer using your product key. If you can't find the old device listed, or if you don't remember your Microsoft account password, contact Microsoft support — they can deactivate the old installation remotely after you verify ownership of the license.

Finding your product key if you've lost it

If you bought a perpetual license but don't have the product key, there are several places to look. Check your email for the original receipt from Microsoft or the retailer you bought it from — the key is usually in that message. If you bought it in a store, check any physical documentation that came in the box.

If you still have Office installed on the old computer, the key is stored there. Open any Office app, go to File > Account, and look for "Product Key" or "About Office" — the key displays as a 25-character code. You can also use a free key-finder tool like Belarc Advisor or Magical Jelly Bean Keyfinder to scan your computer and retrieve the key automatically.

If none of these work, sign into your Microsoft account at account.microsoft.com and go to Services & subscriptions. Your perpetual licenses appear there with their product keys. If your license doesn't show up, it may not be linked to that account — try signing in with a different email address you've used with Microsoft, or contact support with proof of purchase.

Troubleshooting activation problems

If Office installs but won't activate, the most common cause is a network connection issue. Make sure your new computer is connected to the internet, then open any Office app and go to File > Account > Update Options > Update Now. This forces Office to contact the activation servers.

If you see an error saying your product key is invalid or already in use, the key may be linked to a different Microsoft account than the one you're signing in with. Sign out, then sign in with the email address you used when you first bought the license. If you're not sure which account that is, try the email on your original receipt.

If activation still fails after restarting and reconnecting to the internet, Office may need to be reinstalled. Uninstall it completely, restart the computer, then download and install it again. During reinstallation, enter your product key carefully — one wrong character will cause activation to fail. After installation, sign in with your Microsoft account and let activation run automatically.

What happens to your old installation

Once you move your license to a new computer, Office on the old computer will eventually stop working. For Microsoft 365, this happens within a few days if you don't sign in. For perpetual licenses, Office continues to run but shows a warning that the license is in use elsewhere, and some features may be disabled.

You don't need to do anything to force this — it happens automatically as Microsoft's servers detect that your license is active on a different device. If you want to speed it up or ensure the old computer is fully deactivated, uninstall Office from the old machine before you move the license. This is especially important if you're selling or giving away the old computer, because it prevents the next owner from accessing your Microsoft account or your Office files.

Frequently Asked Questions

Can I use the same Microsoft Office license on two computers at once?

Yes, if you have Microsoft 365 — you can install it on up to five devices and use it on all of them, as long as only one person is signed in at a time. With a perpetual license (Office 2019, 2021), you can only use it on one computer at a time. If you install it on a second computer, the first one will show an error.

Do I need to uninstall Office from my old computer before installing it on a new one?

For Microsoft 365, no — you can leave it installed on the old computer and it will deactivate automatically within a few days. For a perpetual license, you should uninstall it from the old computer first to avoid activation conflicts. If you can't access the old computer, contact Microsoft support to deactivate it remotely.

What if I buy a new computer that comes with Office pre-installed?

If the new computer has Microsoft 365 pre-installed, it usually comes with a trial or a limited subscription. Sign in with your own Microsoft account to replace it with your full subscription. If it has a perpetual license (Office 2019 or 2021), you can keep it or replace it with your own license — you can't have two licenses active on the same computer.

Will my documents and settings move to the new computer automatically?

Your Office license moves, but your documents and settings do not. You'll need to copy your files separately — either by moving them from the old computer, downloading them from OneDrive or SharePoint, or using Windows migration tools. Your Office settings (like custom toolbars or AutoCorrect entries) are stored locally and won't transfer unless you manually export them.

Can I move my license if I bought Office from a third-party retailer?

Yes. Licenses bought from retailers like Amazon, Best Buy, or Costco work the same way as licenses bought directly from Microsoft. You'll have a product key in your receipt or email. Sign into your Microsoft account, link the key to your account, and you can move it to a new computer the same way as any other perpetual license.