Office 365

【Office 365】How many devices can I install Office on?

Desktop Office activates on up to 5 devices at once. How the limit is counted, and how to view and sign out old devices to free up slots.

How many devices can I install Office on?

Desktop Office can be signed in and activated on up to 5 devices at once, counting Windows PCs and Macs together. The web apps at office.com don't use a slot and work anywhere.

How slots are counted

Each computer where you've signed in and activated desktop Office takes one slot.
Old records can linger after you replace a computer or reinstall the OS, so it's worth cleaning up your device list occasionally.
The 5-device limit belongs to your seat alone — other family members' devices never eat into your quota.

View and manage signed-in devices

Go to account.microsoft.com and sign in.
Open the Devices tab to see every computer and mobile device linked to your account.
For devices you no longer use, click Remove (or Unlink) under that device.

Sign out directly on a device

If you still have the old device in hand:

Open any Office app, such as Word.
Go to File → Account and click Sign out under the account info.
Office on that device drops to read-only mode and the slot is freed.

Common questions

What happens when I sign in on a sixth device? Microsoft shows an activation-limit prompt and lets you pick an older device to sign out, right there in the dialog — no manual cleanup needed.
Do my phone and iPad count toward the 5? Mobile apps have their own separate allowance (up to 5 phones plus 5 tablets) and don't share the desktop limit.
Will signing out delete my files? No. Files stay on the device or in OneDrive; signing back in restores editing.