Office 2021 end of support is Tuesday 13 October 2026, the same day as Microsoft’s October Patch Tuesday. After that date Microsoft stops issuing security fixes and bug fixes for it. The apps won’t stop working, which is exactly why it’s easy to miss (Office Watch, 22 September 2026).
If your business bought Office 2021 as a one-off licence rather than a Microsoft 365 subscription, this is for you. Here’s what changes, what doesn’t, and what to do this week.
What actually changes on 13 October
Office 2021 follows Microsoft’s Modern Lifecycle Policy, and its lifecycle page shows support ending in October 2026 (Microsoft Lifecycle, Office 2021, checked 5 October 2026). It covers the Home and Business, Home and Student and Professional editions, and the LTSC (long-term servicing) versions are included too, according to Office Watch.
Word, Excel and Outlook will open on 14 October exactly as they did on 12 October. What stops is the stream of security fixes. New weaknesses found in Office after that date stay open on your machines.
That matters because Office is where people open attachments from strangers. An email-borne attack that targets an unpatched Office app has a much easier job.
Check what you actually have
Start with an inventory. For each PC, find out which version of Office it runs. It’s usually under File, then Account, in any Office app.
You’re looking for three groups. Microsoft 365 apps, which are subscription-based, keep receiving updates and are not affected by this date. Office 2021 is the group that ends. Anything older, such as Office 2019 or 2016, is already out of support or about to be, so treat it as the same problem arriving earlier.
Small businesses often have a mix, because licences were bought at different times for different people. That’s normal. It’s just worth knowing before the 13th rather than after.
Your options
There are three sensible routes, and the right one depends on how your business works.
Move to Microsoft 365. This is the route most businesses end up on. You get apps that update themselves, plus email, Teams and cloud storage, on a per-user subscription. If your Office 2021 licences came with older hardware, this is also a chance to retire it.
Buy a newer one-off version. This is possible, but it just puts you on the same treadmill again with a new end date. It suits a business with a specific reason to avoid subscriptions.
Do nothing, knowingly. Some machines, such as one that never touches email or the internet, may be fine for a while. That has to be a decision somebody made, not an oversight.
Windows 10 is part of the same conversation
This date lands alongside Windows 10. Standard support for Windows 10 ended on 14 October 2025. Businesses that wanted more time could buy Extended Security Updates (ESU) by the year, up to three years, and ESU does not include technical support (Microsoft Learn, Windows 10 ESU).
Reseller coverage puts the end of ESU Year One at 13 October 2026 too (Schneider IT Management, 2026), so if you bought ESU a year ago, check your agreement now. Microsoft says Microsoft 365 Apps on Windows 10 will keep getting security updates until 10 October 2028 (Microsoft Support), which helps, but it doesn’t make Windows 10 itself safe to run indefinitely.
An old operating system running old Office is the combination that tends to turn up in a breach report. Fixing the two together is usually cheaper in effort than fixing them one at a time.
The traps that catch small businesses out
Macs count. Microsoft’s lifecycle page lists Office 2021 Home and Business for Mac as well as the Windows editions, so a designer’s iMac with a one-off licence is in the same position as the finance team’s PC (Microsoft Lifecycle, Office 2021).
Shared and spare machines count too. The reception PC that nobody logs into much and the old laptop in the cupboard that gets switched on for payroll are exactly the ones nobody updates.
And licences bought by individual staff or on a previous employee’s account are easy to lose track of. If you can’t say who owns a copy of Office, you can’t say whether it’s covered.
A simple plan for this week
First, list every PC and the Office version on it. Second, mark which users need Office for client work, and which can use the web apps. Third, decide on your route before 13 October, and book the changes in for a quiet week, not a Monday.
If you’d like a hand, we do this kind of checking as part of managed IT support, and an IT assessment will show you the full picture across devices, licences and updates. Speak to Matt about your IT.
Frequently asked questions
When does Office 2021 support end?
Office 2021 support ends on 13 October 2026. After that, Microsoft stops providing security fixes and bug fixes for it.
Will Office 2021 stop working after 13 October 2026?
No. The apps keep working. What stops is technical support and security updates, which is what makes them riskier to use over time.
Is Microsoft 365 affected by the Office 2021 end of support?
No. Microsoft 365 apps are subscription-based and keep receiving updates, so this date does not apply to them.
What should a small business do about Office 2021?
List which PCs run it, then choose a route before 13 October: move those users to Microsoft 365, buy a newer version, or make a recorded decision to keep a machine as it is.
