In short: Redeem your 25-character key at setup.office.com to link it to your Microsoft account, download the installer from your account page, install it, then open Word and sign in with the same Microsoft account to activate. Office 2021 Home & Business for Mac includes Word, Excel, PowerPoint and Outlook for one Mac.
Office 2021 support status: Microsoft ends support for Office 2021 on 13 October 2026. Office 2021 keeps working after that date, but it no longer receives security updates. For a longer-supported version, see Office 2024.
Before you start
Check that your Mac meets the Office 2021 for Mac system requirements:
| Operating system | One of the three most recent versions of macOS |
|---|---|
| Processor | Intel or Apple silicon (M-series) |
| RAM | 4 GB |
| Storage | 10 GB of free space on an APFS or HFS+ formatted drive |
| Display | 1280 x 800 or higher |
| You will also need | An internet connection, a Microsoft account, and your Office 2021 Home & Business for Mac product key |
Use one Microsoft account throughout. The key is tied permanently to the Microsoft account you redeem it with. Choose the account you want to keep, and use it again when you activate.
Step 1: Redeem your product key
- Open setup.office.com in your browser.
- Click Sign in and sign in to your Microsoft account. If you don't have one, choose Create one.
- Enter the 25-character key from your Msckey order email and click Next.
- Select your country or region and language, then confirm. Office 2021 Home & Business now appears in your Microsoft account.
Step 2: Download Office for Mac
- Go to account.microsoft.com/services and sign in with the same Microsoft account.
- Find Office Home & Business 2021 and click Install.
- Click Install again to download the installer package (
.pkg) to your Downloads folder.
Step 3: Install Office
- Open Finder > Downloads and double-click the Office installer package.
- If macOS says the package can't be opened, Control-click it and choose Open.
- Click Continue, review the licence agreement, and click Agree.
- Choose the installation location and click Install. Enter your Mac login password if asked.
- Click Close when you see The installation was successful.
Step 4: Activate Office
- Open Word from Launchpad or the Applications folder.
- Click Get Started, then Sign in, and sign in with the Microsoft account you used in Step 1.
- Office finds your Office 2021 licence and activates Word, Excel, PowerPoint and Outlook together.
- To confirm, open Word > About Microsoft Word. It should show a one-time purchase licence for Office Home & Business 2021.
If activation fails
- "Unlicensed Product" or no licence found: check that you signed in with the same Microsoft account you used to redeem the key. Sign out in Word under Word > Sign Out, then sign in again.
- An older Office or Microsoft 365 licence is still installed: remove other Office versions from Applications before you activate.
- "This product key has already been used": the key is already redeemed. Sign in to account.microsoft.com/services with the account you used first; Office will be listed there.
- Still stuck? Email support@msckey.com with your order number and a screenshot of the error.
Using a Windows PC instead? Follow our Office 2021 Professional Plus guide.
Need an Office 2021 Home & Business for Mac key?
Msckey sells genuine Office 2021 Home & Business for Mac keys with a one-time payment, delivered by email, usually within 1 to 24 hours of payment confirmation.
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