Updating Office 2021 for Mac: How to keep it fully usable beyond July 13, 2026

Do you use Office 2021 for Mac as a one-time purchase, and was your last update a while ago? Then it's worth taking a quick look now. On July 13, 2026, a digital certificate expires that Office apps on the Mac use to verify their license. Older installations then switch to a read-only mode: opening, viewing, and printing remain possible, while editing and saving are paused.

The good news first: with Office 2021 for Mac, this is done in about 10 minutes. All you need is the current app version - and you get that for free. Unlike Office 2019 (more on that below), Office 2021 has a clear path forward.

What happens on July 13, 2026

Office apps on macOS and iOS verify their license via a digital certificate. It's precisely this certificate that expires on July 13, 2026. Apps that have already been updated to a sufficiently new version already carry the renewed certificate within them and keep running normally. Older builds switch to the limited-functionality mode after the deadline.

• Your files remain fully intact and readable - this is purely about the license check.
• Microsoft classifies it as a pure licensing matter; your data and security remain untouched.
• Affected are macOS and iOS/iPadOS. Windows and Android keep running unchanged.
• As soon as the app is on the required version, full functionality returns.

Are you affected? The minimum versions

Your Office 2021 for Mac is affected precisely when it runs below these versions:

The crux with Office 2021 is the app version, less the license: on macOS 12 or newer you grab Build 16.83 (including the renewed certificate) and you're all set. This is exactly where the difference to Office 2019 lies, for which this build version is out of reach - Office 2019 for Mac stays in read-only mode.

Step 1: Check the current version

Before you update anything, check your current status:

• Open any Office app, for example Word.
• In the menu bar, click Word and then "About Word".
• Read off the version number. If it's below 16.83, an update is due.

Tip: Check this for all the apps you use (Word, Excel, PowerPoint, Outlook, OneNote) - the version levels can differ depending on your installation history.

Step 2: Update Office 2021 for Mac

The most direct route is via Microsoft AutoUpdate:

• Open an Office app like Word.
• In the top menu, go to Help and then "Check for Updates".
• Enable "Automatically keep Microsoft Apps up to date" so that future builds arrive on their own.
• Click Update or Update All and install the available updates.

If you installed Office from the Mac App Store, the update runs there instead: App Store, then Updates, then Update All. When in doubt, this Terminal command shows you which route applies: mdls -name kMDItemAppStoreReceiptType /Applications/Microsoft\ Word.app. If it reports "(null)", you use AutoUpdate; if it reports "Production", the App Store.

Step 3: If read-only mode is still shown

Two typical stumbling blocks and their solutions:

• The "Check for Updates" menu item is hidden or hangs: Download the current version of the Microsoft AutoUpdate tool and start the search again afterward.
• Still in read-only mode after the update: Quit the app completely (more than just closing the window), reopen it, and sign out and back in within the app's account settings.

The most common stumbling block: a macOS that's too old

This is where the real catch lies for older installations. The required app update needs macOS 12 Monterey or newer. On macOS 11 Big Sur or older, a macOS upgrade comes first, after which Build 16.83 works.

Good to know for the future: Microsoft maintains Office for the three most recent macOS versions at any given time. Anyone who wants to keep receiving updates long-term should plan the macOS upgrade in right away.

A practical order if your Mac is older:

• Check whether your Mac supports at least macOS 12 (preferably Sonoma).
• Update macOS.
• Then update Office 2021 to 16.83 or newer.
• If your macOS stays on an older version and you want to work permanently without a subscription, Office 2024 for Mac is the clean fresh start as a one-time purchase (requires macOS 14 Sonoma).

Update and support are two different things: a look at October 2026

To keep the two clearly separated: the certificate update takes care of the license check. Product support runs independently of it and ends for Office 2021 for Mac on October 13, 2026.

• If you update to 16.83 or newer now, Office 2021 stays fully usable beyond July 13, 2026 - including editing and saving.
• From October 13, 2026, Office 2021 for Mac will then have reached its final state: it keeps running, but from then on new security updates come with a current version such as Office 2024 for Mac.

Quick checklist for the Office 2021 case

• Check the version: is it below 16.83? Then update.
• Check macOS: at least macOS 12 Monterey? Otherwise update macOS first.
• Run the update via Help, then "Check for Updates" (or through the App Store).
• After the update, restart the app and sign in to your account again if you're still in read-only mode.
• Remember: from October 13, 2026, Office 2021 for Mac is on its final state.

Frequently asked questions

Will my documents be preserved?

Yes. Only the license check is affected. Your files remain fully intact and readable.

Does this also apply to Office 2019 for Mac?

Yes - but there the update leads nowhere: Office 2019 for Mac stays on Build 16.78 and thus below the required 16.83. It remains in read-only mode after July 13, 2026. More on this in the article Office 2019 for Mac is being shut down.

Is Windows affected?

Windows keeps running unchanged. The certificate matter concerns macOS and iOS/iPadOS.

Does the update cost anything?

The app update to Build 16.83 or newer is free for existing Office 2021 licenses.

Sources: Microsoft Learn - Certificate update for Microsoft 365 Apps on macOS/iOS and Microsoft Support - Update Office on macOS/iOS.