Microsoft Office end of support 2026 reached an important milestone yesterday, 13 October 2026, when Office LTSC 2021 and Microsoft Publisher reached the end of support. The entire Office LTSC 2021 family reached end of support, Microsoft Publisher was retired, and the first year of Windows 10 Extended Security Updates came to an end on the same day. If any of your machines still run these products, they are now outside normal support and no longer receive security updates. Here is what it means and what to do about it.
Microsoft Office end of support 2026: what changed on 13 October?
- Office LTSC 2021 – the entire family, including Office LTSC 2021, Project LTSC 2021 and Visio LTSC 2021. There is no extended support option after this date.
- Microsoft Publisher – retired on the same day. Publisher no longer receives updates and is not included in new versions of Microsoft 365 or Office LTSC.
- Windows 10 Extended Security Updates, Year 1 – commercial ESU coverage for the first year ended yesterday. Businesses that enrolled will need Year 2 coverage to keep receiving security updates.
- Windows Server 2012 and 2012 R2 – the third and final year of Extended Security Updates ended, so no further security updates are available on any terms.
- Windows Server 2022 – mainstream support ended. This is a change in support type rather than a cliff: security updates continue under extended support until 14 October 2031.
Why end of support matters for a business
After end of support, a product no longer receives security fixes. New vulnerabilities discovered in Office LTSC 2021 or Publisher will never be patched, which makes any machine still running them a growing risk over time. That matters for three practical reasons:
- Security – unpatched Office applications are a common route for malware delivered through malicious documents.
- Compliance and insurance – Cyber Essentials, cyber insurance policies and many client contracts expect supported software. Running end-of-support Office can affect cover.
- Compatibility – add-ins, printers and line-of-business software are increasingly tested only against current versions, so problems tend to appear gradually rather than all at once.
Is my business affected?
Office LTSC 2021 was popular with businesses that use perpetual licences rather than Microsoft 365 subscriptions – often on shared PCs, factory floor machines, kiosks or older laptops that are not on an upgrade cycle. Publisher, meanwhile, was widely used for leaflets, newsletters and simple print layouts, and many staff will not realise it has been retired until something stops working.
The quickest check is to open any Office application on each machine and look under File > Account, where the product name and version are listed. Anything showing “Office LTSC 2021”, “Office 2021” or “Publisher 2021” (or earlier) is now out of support.
What are the options now?
- Move to Microsoft 365 Apps – the subscription version of Office, always current and included in Microsoft 365 Business Premium. This is the best option for most businesses because it also brings security, management and Copilot Chat alongside the apps.
- Move to Office LTSC 2024 – the current perpetual-licence version, supported until 2029. This suits machines that must stay offline or cannot take a subscription, but it is a fixed-term purchase rather than a long-term answer.
- Replace Publisher – Microsoft points users towards Word, PowerPoint or Microsoft Designer for print-style layouts. Existing .pub files can be opened in Publisher 2021 for now, but plan to move templates across to a supported tool.
- Plan Windows 10 ESU Year 2 – if you enrolled in ESU Year 1, arrange Year 2 coverage or accelerate the move to Windows 11. Devices left without coverage since 13 October 2026 are unpatched.
What should KES customers do?
If KES manages your Microsoft 365 environment, we can identify which of your devices are still running Office LTSC 2021, Publisher or unsupported Windows versions, and put a plan in place to move them across with minimal disruption. If you would like that checked, get in touch – or ask us to include it as part of a wider Microsoft 365 security review.
The key point is not to panic: nothing stopped working yesterday. But from 13 October 2026, every machine still on these products is slowly becoming a liability, and the cheapest time to deal with it is before something goes wrong.
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Still Running Office LTSC 2021 or Publisher?
Since yesterday these products no longer receive security updates. KES can check which of your devices are affected and move them onto supported software before they become a risk.
Tell us how many machines you have and we will identify which ones are now out of support and what the cheapest fix is.
Contact KES →