On October 13, 2026, Microsoft ended support for Office 2021 and Office LTSC 2021. The apps still open, but they no longer get security fixes, which matters because Word, Excel and Outlook are where much of a business’s email and attachments get opened.
What happened
Office 2021 came in two forms: retail and small-business editions (Office Home & Business 2021, for example) and the volume-licensed Office LTSC 2021 that many organizations use on shared or locked-down PCs. Both reached end of support on the same day. That covers Word, Excel, PowerPoint, Outlook, Access, OneNote and Publisher, plus Project 2021 and Visio 2021.
Microsoft says that after end of support there are “no new security updates, non-security updates, free or paid assisted support options.” Unlike Windows 10, Office has no paid Extended Security Updates program to buy you time.
Microsoft has also taken Office LTSC 2021 off its list of versions supported for connecting to Microsoft 365 services like Exchange Online, SharePoint and OneDrive. It notes that older versions “might still be able to connect,” but that connection isn’t supported. Translation: Outlook 2021 will probably keep syncing your mailbox until the day it doesn’t, and that day won’t come with a warning.
What it means for you
- Security exposure grows over time. Office documents are a common way for attackers to get in. A newly found flaw in an unsupported version stays unpatched.
- Reliability drifts. Microsoft updates its cloud services constantly and doesn’t test them against unsupported clients. You may see sync errors or sign-in problems that no one can fix.
- Audits and cyber insurance. Many security questionnaires ask whether all software is vendor-supported. “Mostly” tends not to be a satisfying answer.
- It was a short run. LTSC 2021 got five years of support, compared with seven for Office 2019 and ten for Office 2016. If you budgeted for a longer life, you aren’t alone.
Your options
1. Move to a Microsoft 365 subscription. This is Microsoft’s preferred path. The apps update continuously, so you won’t face another end-of-support date. For organizations under 300 users, Microsoft points to Microsoft 365 Business Premium, Business Standard or Apps for business. Larger organizations typically look at Microsoft 365 E3, Office 365 E3 or Apps for enterprise.
2. Move to Office LTSC 2024. This is the current perpetual version, sold through volume licensing, and Microsoft recommends it for computers that can’t run a subscription, such as offline, regulated or shop-floor PCs. Support and Microsoft 365 connectivity run until October 9, 2029. That’s three years, so plan the next move now.
3. Mix both. Many organizations put most users on subscriptions and keep LTSC for a few special-purpose machines. A short inventory usually shows where the line falls.
What we recommend
- Find every copy. Check Office versions across desktops, laptops, kiosks and shared PCs. The ones nobody remembers installing tend to be the ones still running Office 2021.
- Start with Outlook. Machines that connect to Microsoft 365 email and file storage are the most exposed, so move them first.
- Match licenses to roles. Not everyone needs the same plan. Matching plans to how people actually work can avoid paying for features nobody uses.
- Check add-ins and macros. Test critical spreadsheets, templates and line-of-business add-ins on the new version before you roll it out.
- Bundle it with your Windows 10 plan. If you’re replacing PCs or paying for Windows 10 Extended Security Updates, plan the Office upgrade at the same time. One project is easier than two.
How DTM can help
We work with Microsoft licensing every day, alongside the hardware it runs on. DTM can help you compare subscription and perpetual options, check for promotions while they’re available, and match the right plan to each group of users. If the Office upgrade comes with new PCs, we can source those too, from whichever manufacturer fits your needs.
Not sure what’s still running Office 2021? Contact us and we’ll help you sort it out.
Microsoft licensing terms, plans, promotions and lifecycle dates can change. Check current details before you buy.