Office messages are often vague: unlicensed product, activation required, or sign in to activate. Behind them, the subscription may have expired, the account may be wrong, a product key may not be linked, or an organization license may be unable to reach the internal network. You have to know the product type before the message means anything.
Four product lines
| Type | How you pay | The license follows | Typical message |
|---|---|---|---|
| Microsoft 365 subscription | Monthly or yearly | The Microsoft account | Sign in to activate, or subscription expired |
| One-time purchase (2021 or 2019) | Paid once | The account used for first activation, usually one device | Enter a product key |
| Volume licensing | Purchased by the organization | The organization’s KMS host, or a MAK | Unlicensed product |
| Preinstalled on the device | Included with the device | The device and the redemption account | Activation required |
Subscription: the license follows the account
Microsoft 365 does not write the license into the device. It checks the account each time you sign in. On the same PC, an account with a subscription works, and an account without one is told it is unlicensed. That is a common reason it works on another computer but not on this one.
A subscription has to be checked online from time to time. After a long time offline, Office may briefly show as unlicensed. It usually recovers after you are online and sign in again.
One-time purchase: the product key is used once
One-time editions such as Office 2021 and Office 2019 need a 25-character product key, and the first activation links it to a Microsoft account. After that link, the product key usually cannot be used on a second account.
Volume licensing: the organization is in control
Volume-licensed Office activates through the organization’s KMS host, and the client is managed with ospp.vbs. It does not recognize a personal account, and signing in to a Microsoft account does not activate it.
These editions usually show the organization name under File, then Account. When you see that line, the problem almost certainly needs the organization’s administrator. On your side, you can check the network and pass along what you found.
Preinstalled: do not skip redemption
Office that comes with a new PC often has to be redeemed by signing in the first time you open it, or the manufacturer activates it in advance. If that step was skipped, Office keeps asking to be activated. Some preinstalled editions also have a redemption deadline, and after it passes the only path is to buy a license.
Match the message to the next step
| What you see | More likely | Next step |
|---|---|---|
| An organization name | Volume licensing | Check the internal network, or contact IT |
| Subscription expired | The subscription has ended | Renew it, or use another license |
| Enter a product key | A one-time purchase | Find the key in the purchase record |
| It keeps asking you to sign in | The account does not match | Sign in with the account used for the purchase |
This article is based on the Office activation guidance on Microsoft Support, the Microsoft Learn documentation for the Office volume activation management tool, and the documentation for resetting activation state. Product names and on-screen wording can change with updates.
- Activate OfficeMicrosoft Support · Applies to: Office 2016 and later / Microsoft 365 · Checked 2026-10-20
- Tools to manage volume activation of OfficeMicrosoft Learn · Applies to: Office volume activation (ospp.vbs) · Checked 2026-10-20
- Reset Microsoft 365 Apps for enterprise activation stateMicrosoft Learn · Applies to: Reset Microsoft 365 Apps activation state · Checked 2026-10-20
A few questions show which case you are in, and what to do next.