How sign in works in Microsoft 365

If you subscribe to Microsoft 365, you'll be prompted to sign in to use Office after installation, or after you sign out. Your subscription has a sign-in limit that determines how many Office installs you can sign in to at the same time. Use the tabs below to select your subscription type and learn more about sign-in limits for your subscription.

With Microsoft 365, you can install Office on all your devices and sign in to Office on five devices at the same time. This includes any combination of PCs, Macs, tablets, and phones.

Get help signing in to Office

Illustrates how a user can install Office on all their devices and can be signed in to five at the same time

Here's what you need to know

Here are some tips for using Microsoft 365 on multiple devices:

  • Each person who uses Office on a device must have an account that's associated with Microsoft 365. This can be the account that subscribes to Microsoft 365, or any accounts that share a Microsoft 365 Family subscription.

  • When you install Office on a device, you'll be prompted to sign in the first time you start an Office app.

  • Office remains activated as long as you're signed in. If you sign out, you'll be prompted to sign in again.

  • If you have more than five devices, Office will sign you out of devices automatically to stay within your sign-in limit. To use Office on a device where you've been signed out, just sign back in.

Common questions

I signed in. Should I stay signed in?

We recommend staying signed in to Office. If you sign out, Office will prompt you periodically to sign in.

What happens if I sign out of Office?

You might lose some subscription features if you sign out. We recommend that you stay signed in to Office on the devices you use the most.

If I share Microsoft 365 Family, how does signing in work?

You can share your Microsoft 365 Family subscription with up to five other people. Each person on the subscription can install Office on all their devices and be signed in to five at the same time.

Get help sharing your subscription

Can other people sign in to Office on my device?

If a person signs in to Office on your device without a subscription, Office will run in read-only mode. If you have Microsoft 365 Family, you can share your subscription with five additional people. Each person can sign in to your device and use Office after you share your subscription with them.

Get help sharing your subscription

With Microsoft 365, you can install and sign in to Office on 5 PCs or Macs, 5 tablets, and 5 phones.

Get help signing in to Office

Here's what you need to know

Here are some tips for using Microsoft 365 on multiple devices:

  • If you sign in to Windows using your work or school account, you'll be signed in to Office automatically. On Macs and mobile devices, sign in using your work or school account to activate Office.

  • Office remains activated as long as you're signed in. If you sign out, you'll be prompted to sign in again.

  • Office will sign you out of devices automatically to stay within your sign-in limit. To use Office on a device where you've been signed out, just sign back in.

Common questions

I signed in. Should I stay signed in?

We recommend staying signed in to Office. If you sign out, Office will prompt you periodically to sign in.

What happens if I sign out of Office?

You might lose some subscription features if you sign out. We recommend that you stay signed in to Office on the devices you use the most.

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