Microsoft Office

Office 2021 end of support and what it means for your PCs

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Office 2021 received its last security update on 13 October 2026. Microsoft ended support for Office LTSC 2021, Project 2021 and Visio 2021 on the same day, which was October’s Patch Tuesday, and for the Home and Pro editions of Windows 11 version 24H2. A copy of Office 2021 still opens and stays activated after that date. It no longer gets security updates or technical support, and Microsoft no longer supports it for connecting to Microsoft 365 services such as Exchange Online, SharePoint Online and OneDrive.

If you want to stay with a one-time purchase, the replacement is Office LTSC 2024, which Microsoft supports until 9 October 2029. A Microsoft 365 subscription is the other way to stay on a supported version.

Products that reached end of support on 13 October 2026

Microsoft’s notice to Microsoft 365 administrators, message MC1472429, set the date for Office LTSC 2021 and confirmed that Project 2021, Visio 2021 and several other products end on the same day. For home users and small businesses, these are the versions affected.

  • Office Home & Student 2021 and Office Home & Business 2021, on Windows and Mac
  • Office Professional 2021
  • Office LTSC Standard 2021 and Office LTSC Professional Plus 2021
  • Office LTSC Standard for Mac 2021
  • The standalone 2021 apps, such as Word 2021, Excel 2021 and Outlook 2021
  • Project Standard 2021 and Project Professional 2021
  • Visio Standard 2021 and Visio Professional 2021
  • Windows 11 version 24H2 in the Home and Pro editions

Office 2016 and Office 2019 had already reached the end on 14 October 2025, which leaves the 2024 release as the only one-time version of Office still in support. Office 2021 and Office 2024 each get five years with no extended phase afterwards. Microsoft’s overview of the current release says “Office LTSC 2024, including Project and Visio, receive five years of Mainstream Support. After this period, there will be no Extended Support for these products.”

Office 2021 keeps running, without updates

Word, Excel, PowerPoint and Outlook 2021 start as usual after the end of support date, documents open and save, and an activated licence stays activated. Microsoft’s notice says that updates, security updates and technical support all end, while “the applications may continue to function”.

The loss of security updates is the part to take seriously. Documents and email attachments have long been one of the ways malicious code reaches a PC, and any vulnerability found in the 2021 apps from now on stays open on every PC that still runs them. Microsoft’s support teams also stop helping with problems in the 2021 versions.

Outlook 2021 and Microsoft 365 mailboxes

The change most likely to show up in daily use concerns Microsoft 365 services. Microsoft publishes a table of the Office versions it supports for connecting to Exchange Online, SharePoint Online and OneDrive, and the last supported date it gives for Office LTSC 2021 is 13 October 2026.

Connections aren’t blocked. Microsoft’s page says “Older Office versions might still be able to connect to Microsoft 365 services, but that connectivity isn’t supported.” It explains that changes to its services aren’t tested against older versions, and warns that “over time, these older versions might encounter other unexpected performance or reliability issues while using Microsoft 365 services.”

Outlook 2021 will carry on sending and receiving mail from a Microsoft 365 mailbox for now. If a change on the Exchange Online side stops something working in Outlook 2021, Microsoft won’t offer support for it. Office LTSC 2024 stays on the supported list until 9 October 2029, the same date its security updates end.

Windows 11 version 24H2 Home and Pro

Windows 11 version 24H2 in the Home and Pro editions got its final update on the same Patch Tuesday. Microsoft’s notice said “The October 2026 monthly security update is the last update available for these editions.” The Enterprise and Education editions of 24H2 are supported until 12 October 2027.

Moving to a newer version of Windows 11 costs nothing and happens through Windows Update. The current version, 26H2, was released on 29 September 2026. On a PC already running 24H2 or 25H2 it installs as an enablement package, a small update that switches on features already delivered in earlier monthly updates. It downloads and installs on its own and needs one restart.

The rollout is gradual, so not every PC is offered 26H2 straight away. Open Settings > Windows Update and select Check for updates. Turning on Get the latest updates as soon as they’re available, on the same page, makes Windows offer 26H2 as soon as it is ready for that PC.

Publisher reached end of life in the same month

Publisher had its own deadline. Microsoft’s support page says “In October 2026, Microsoft Publisher will reach its end of life.” Subscribers lost it first. Microsoft 365 users can no longer open or edit .pub files in Publisher, and Windows Latest reported in August 2026 that access through Microsoft 365 would end on 2 October.

One-time versions carry on. According to Microsoft, “If you have the Perpetual version of Publisher, you will still be able to access and edit your files.” Publisher 2021 still opens .pub files, but it shares Office 2021’s end of support and gets no more security updates. No current version of Office includes Publisher, and Office LTSC 2024 never did.

Microsoft recommends converting existing Publisher files to PDF or Word format. Do it before Office 2021 comes off the PC, because nothing in Office 2024 opens a .pub file.

Project Online closed on 30 September 2026

Project Online retired two weeks before the Office deadline. Microsoft’s lifecycle page gives the retirement date as 30 September 2026. The retirement was announced in September 2025, new sales stopped on 1 October 2025, and plans stored in Project Online are no longer accessible.

The Project desktop app isn’t affected. Project 2024 still opens and saves .mpp files on your own PC or file server, and Project Server Subscription Edition is still supported for organisations that want a shared project server. Project Server 2016 and Project Server 2019 are no longer an option, having reached the end of extended support on 14 July 2026.

Windows 10 consumer ESU now runs to October 2027

Consumer Extended Security Updates for Windows 10 were first sold as a one-year programme ending in October 2026. In June 2026 Microsoft extended the programme by a year. Its ESU page now says “You can enroll in ESU any time until the program ends on October 12, 2027.” PCs that were already enrolled stay covered to the new date without anyone having to do anything.

Enrolment is free if you sync your PC settings to a Microsoft account. The other options are 1,000 Microsoft Rewards points or a one-time payment of $30 or the local equivalent. In the European Economic Area enrolment is free with a Microsoft account sign-in. One ESU licence can be used on up to 10 devices.

The consumer programme is for personal PCs. Microsoft doesn’t offer it on PCs in kiosk mode, PCs joined to an Active Directory domain or to Microsoft Entra, or PCs enrolled in a mobile device management service, although Entra registered devices can use it. Businesses buy ESU through Microsoft volume licensing at $61 per device for the first year, with the price doubling each year for a maximum of three years.

ESU keeps Windows 10 patched and does nothing for Office 2021.

Replacing Office 2021

For a one-time purchase, Office LTSC 2024 is the direct successor. It is licensed per device, gets security updates until 9 October 2029, and has the same core apps as Office 2021 (Word, Excel, PowerPoint, Outlook and OneNote), with Access in the Professional Plus edition. Publisher is the only app that has gone.

If nobody on the PC uses Access, Office LTSC Standard 2024 covers everything Office Home & Business 2021 or Office LTSC Standard 2021 did. If someone opens or maintains an Access database, choose Office LTSC Professional Plus 2024. Our comparison of Office LTSC Standard and Professional Plus 2024 sets out the difference app by app.

On a Mac, Office LTSC Standard for Mac 2024 replaces both Office 2021 for Mac and Office LTSC for Mac 2021.

Project 2021 users can move to Project Professional 2024, supported until the same date in 2029. Our guide to Project Professional and Project Standard 2024 explains when the Professional features earn their price.

Visio 2021 users can move to Visio Professional 2024, also supported until 9 October 2029. It has to use the same architecture and update channel as the Office on the PC, and our comparison of Visio Professional and Visio Standard 2024 explains what Professional adds.

A Microsoft 365 subscription stays supported for as long as you pay for it and keep the apps on a supported version. We worked out the costs over the three years to October 2029, at Microsoft’s UK prices, in our cost comparison of Office LTSC 2024 and Microsoft 365.

The Office 365 Pro Account we sell is a preconfigured Microsoft 365 account, so it sits on the subscription side of this choice. Continued use depends on the Microsoft 365 subscription behind the account staying active, as its product page explains. Its apps can’t be installed on the same Windows PC as Office LTSC 2024, and our guide to Office LTSC 2024 and Microsoft 365 on one PC explains why.

Before you uninstall Office 2021

  • Convert your Publisher files to PDF or Word while Publisher 2021 is still installed.
  • Remove every Office 2021 app before installing Office LTSC 2024. Office LTSC 2024 can only use the PerpetualVL2024 update channel, which no version of Office 2021 uses, and Microsoft’s rule is “Products installed on the same computer must use the same update channel.” Go to Settings > Apps > Installed apps, uninstall each Office 2021 entry, then restart.
  • Choose 32-bit or 64-bit once and keep to it. Microsoft requires every Office product on a PC to use the same one, so Project or Visio added later has to match the Office you install now.
  • Test any old workbooks or documents that rely on ActiveX controls. Microsoft’s overview says “In Office LTSC 2024, ActiveX controls are disabled by default. However, IT administrators can re-enable ActiveX where necessary.”
  • Keep your proof of purchase with the PC’s records.

Office LTSC 2024 installs with the Office Deployment Tool, and our Office LTSC 2024 installation guide has a configuration file ready to adapt.

Questions about Office 2021 end of support

Does Office 2021 stop working after 13 October 2026?

No. The apps keep running and an activated copy stays activated. Microsoft has stopped releasing security updates for them and no longer provides technical support.

Which versions of Office are still supported?

Office 2024 and Office LTSC 2024, on Windows and Mac, are supported until 9 October 2029, and so are Project 2024 and Visio 2024. Microsoft 365 Apps stays supported for as long as the subscription is active and the installed version is a supported one.

Do I need to uninstall Office 2021 before installing Office 2024?

Yes, for Office LTSC 2024. It can only use the PerpetualVL2024 update channel, no version of Office 2021 uses that channel, and Microsoft requires every Office product on a PC to use the same one.

Does Windows 10 ESU include updates for Office 2021?

No. Extended Security Updates cover Windows 10 itself. Office 2021 has its own end date, which has now passed.

Can Outlook 2021 still connect to a Microsoft 365 mailbox?

It can for now. Microsoft no longer supports the connection, so a change on the Microsoft 365 side can stop a feature working without warning.

Sources

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Choosing between Office LTSC Standard 2024 and Professional Plus 2024
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