Official-source guide

Office 2021 Professional Plus Activation Guide

Guide for redeeming and installing Office 2021 Professional Plus using Microsoft official setup pages and activation prompts.

DifficultyEasy
Estimated time10 minutes
License typeProduct key
Last verifiedJul 7, 2026
Guide statusVerified

Before you start

Sign in with the Microsoft account you want to associate with the license, redeem the key on the official Office setup page when applicable, then install and activate Office.

Activation steps

Open the Office setup page

Go to the official Microsoft Office setup page and sign in with your Microsoft account.

Open the Office setup page illustration

Redeem the product key

Enter the product key exactly as delivered, then continue through Microsoft’s setup flow.

Redeem the product key illustration

Download and install Office

After redemption, download and install the Office apps from your Microsoft account or the setup page.

Download and install Office illustration

Open an Office app to activate

Open Word, Excel, or another Office app and follow the activation prompt if it appears.

Open an Office app to activate illustration

Troubleshooting

Wrong Microsoft account

Use the account that redeemed the product key. A key can usually only be redeemed once.

Activation wizard appears

Follow the Microsoft Activation Wizard prompts and sign in with the correct account.

FAQ

Where do I enter an Office key?

Microsoft directs customers to the correct setup site for their Office product key.