Installing Word on old MacBook (BigSur)

Question

Hello,

I am trying to install word on a 2015 MacBook running the latest BigSur OS - 11.7.11. I have tried to download a few Office Suites from the Update History for Office and Mac page after reading an article called Most Recent Office You Can Run – Best Practices and downloaded Office 16.77 as this was stated to be the most recent office that can run. However after installing a Microsoft AutoUpdate box popped up that stated for everything except Teams and OneDrive a MacOs upgrade was required - to 14.0 or later. I then tried again with a few older suites, going down to 16.5 something, however it has always stated that a MacOs upgrade is required. Is there a way I can download word?

Thanks!

Answer 1

Word can still be installed and used on that MacBook; the issue is that Microsoft AutoUpdate is trying to move Office to a newer build that no longer supports Big Sur.

Key points from current support policy:

• Microsoft 365 for Mac and Office 2021/2024 for Mac support only the three most recent macOS versions.
• As of September 2025 those are macOS Tahoe (26), Sequoia (15), and Sonoma (14).
• Starting with the September 2025 update (16.101), macOS Sonoma or later is required to receive updates to Word, Excel, PowerPoint, Outlook, and OneNote.
• Older macOS versions (like Big Sur 11) can still run Office, but will not receive newer updates once support moves on.

What this means for Big Sur:

• Big Sur is older than the currently supported three macOS versions, so the latest Office builds (including what AutoUpdate is offering) require macOS 14 or later.
• A compatible, older Office build must be installed and then kept at that version (or within the last version that supported Big Sur). AutoUpdate will report that a macOS upgrade is required for newer builds, but that does not prevent using the already-installed Word.

Practical steps:

1. Install an Office build that is known to run on Big Sur (such as the 16.7x range referenced in “Most Recent Office You Can Run – Best Practices”).
2. After installation, when Microsoft AutoUpdate offers newer updates that require macOS 14 or later, decline or turn off automatic updates so the apps stay on the last Big Sur–compatible version.
3. Word, Excel, etc. should open and run on Big Sur even though newer updates are blocked. Functionality may be limited compared to current builds, and security updates will eventually stop, but the apps remain usable.

If installation itself fails (not just updating):

• Verify system requirements using System requirements for Office.
• If the installer download is failing or corrupted, follow the guidance in “What to try if you can't install or activate Office for Mac” (for example, re-download using Safari and ensure the internet connection is working).

There is no way to install the very latest Office builds on Big Sur; only the most recent build that still supported that macOS version can be used, and AutoUpdate messages about needing macOS 14 or later can be ignored as long as Word itself launches and runs.

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References:

• Upgrade macOS to continue receiving Microsoft 365 and Office for Mac updates
• What to try if you can't install or activate Office for Mac
• How do I upgrade Office?
• Troubleshoot installing Office
• How to download Microsoft office (not 365) to MacOS Venture 13.7.8 - Microsoft Q&A
• how to download word for new mac - Microsoft Q&A
• Help! I can't get 365 to work. Can I use it on my MacOS or do I need Office? - Microsoft Q&A
• MS Office on my 2014 MacBook - Microsoft Q&A
• Cannot install Microsoft 365 because my os is too old - Microsoft Q&A