Office 2021 end of support arrives on October 13, 2026, the same Patch Tuesday that ends servicing for Windows 11 version 24H2. The Windows date has been circled on calendars for a year. The Office date has not, and in the environments we work in it is the one more likely to cause a problem.
Seven separate Microsoft lifecycle events land that day. Most coverage names one of them.
We wrote about the Microsoft SMS MFA retirement in August and Drupal 10 end of life in May. This is the same category of problem and a bigger one, because it touches the desktop fleet rather than a single platform.
Everything that ends on October 13
Microsoft’s own end of support index for 2026 lists the full set. Grouped by what kind of ending it is:
End of servicing, meaning the product lives on but this version stops receiving updates:
- Windows 11 version 24H2, Home and Pro editions
- Dynamics 365 Business Central on premises, 2025 release wave 1, version 26.x
End of support, meaning the product itself is finished:
- Office 2021 and Office LTSC 2021, the entire family: Access, Excel, OneNote, Outlook, PowerPoint, Publisher, Visio and Word, plus Project 2021 and Office LTSC 2021 for Mac
- Skype for Business LTSC 2021
- Windows 10 2016 LTSB and Windows 10 IoT Enterprise LTSB 2016
- Windows Server 2012 and Windows Server 2012 R2, Extended Security Update Year 3
A phase change rather than an ending:
- Windows Server 2022 moves from mainstream support to extended support, so security fixes continue and non-security updates stop
The distinction between the first two groups matters more than it sounds. A Windows 11 version reaching end of servicing means you move to a newer version of Windows 11. A product reaching end of support means there is nothing newer inside that product to move to. Office 2021 is in the second group.
Office 2021 end of support is the one that will bite
Perpetual Office is everywhere in the organizations we serve, and it is invisible in most inventory reports because nobody thinks of it as infrastructure.
The pattern is familiar: a nonprofit or an association bought Office 2021 outright in 2021 or 2022 rather than committing to a per-seat subscription, installed it across twenty or forty machines, and has not thought about it since. It works. It opens documents. There is no renewal notice because there is nothing to renew. The Office 2021 end of support date does not appear in a billing cycle, so it does not appear in a budget conversation.
Both lines end together. The retail and volume perpetual Office 2021 products are listed under "Product retirements," and the Office LTSC 2021 family is listed under "Products reaching end of support." Same date, same outcome: no more security updates for Word, Excel, Outlook, PowerPoint or the rest.
Outlook is the part that should concern anyone running a mail estate. An unpatched mail client parsing untrusted content is a different risk profile from an unpatched spreadsheet, and Outlook 2021 will be parsing untrusted content every hour of every working day from October 14 onward.
Skype for Business Server LTSC 2021 going the same day is worth a check too. It is rarer than it used to be and not as rare as people assume in associations that built a conferencing setup before 2020 and never dismantled it.
The Windows 10 ESU date most people are quoting is wrong
This one has been circulating in two different wrong versions, and it is worth getting right before it reaches a client.
Windows 10 consumer Extended Security Updates do not end in October 2026. Microsoft’s consumer ESU page says, verbatim: "Windows 10 support has ended. You can enroll in ESU any time until the program ends on October 12, 2027."
October 12, 2027. Not October 13, 2026, which is the original one-year end date and is what a great deal of guidance written in 2025 still says. And not October 13, 2027, which is the date you get if you assume a clean twelve-month extension and do not check.
Consumer ESU was extended quietly. Microsoft edited the page in late June 2026 without a formal announcement post, which is why stale guidance is still in wide circulation and why the correction has not propagated. The live page is the source of truth here, and it is unambiguous.
Three ways in, all from Microsoft’s own list: at no additional cost if the PC is syncing settings through Windows Backup, by redeeming 1,000 Microsoft Rewards points, or by a one time purchase of thirty dollars. One license covers up to ten devices. The device has to be on Windows 10 version 22H2, and the Microsoft account used to sign in has to be an administrator account, which rules out machines running on local accounts and machines that are domain joined.
Commercial ESU is cumulative, and education pays one dollar
The commercial program is a different animal from the consumer one, and two things about it are routinely missed.
Year 1 ran from October 15, 2025 to October 13, 2026. Year 2 runs from October 14, 2026 to October 12, 2027. Year 3 runs from October 13, 2027 to October 10, 2028. Those dates come from Microsoft’s Partner Center documentation.
Microsoft publishes one price and one rule: "Extended Security Updates for organizations and businesses on Windows 10 can be purchased today through the Microsoft Volume Licensing Program, at $61 USD per device for Year One," and "the price doubles every consecutive year, for a maximum of three years." So Year 2 is 122 dollars and Year 3 is 244 dollars. Microsoft does not print those two numbers anywhere we could find; they follow from the doubling rule.
The rule people get wrong is that it is cumulative, not a renewal. Microsoft’s own wording: "If you decide to purchase the program in Year Two, you have to pay for Year One too, as ESUs are cumulative." An organization that skipped Year 1 and wants coverage starting October 14 pays 61 plus 122, which is 183 dollars per device, not 122.
Now the part worth auditing today. Microsoft’s education pricing for the same program, published on the Microsoft Education blog, is "$1 per device for the first year, $2 the following year, and $4 the third year," and it is "extended to all education customers, including K-12 and higher education."
One dollar against sixty one. Any institution that qualifies as a Microsoft education customer and is paying the commercial rate is overpaying by roughly sixty times. That is worth a purchase order review this week rather than next quarter.
Nonprofits get nothing equivalent. We checked Microsoft’s nonprofit offers page and its FAQ, and neither mentions Extended Security Updates at all. There is no nonprofit ESU discount. What exists instead is a device licensing grant of up to 50 Windows 11 Pro licenses through TechSoup, with discounted pricing beyond that through any Cloud Solution Provider. TechSoup does carry all three ESU years in its catalog as separate products, but we could not retrieve the admin fee, so get that number from TechSoup directly rather than from anyone quoting it secondhand.
The strategic read for a nonprofit is straightforward. The Windows 11 Pro grant is the better answer wherever the hardware supports Windows 11. ESU is worth buying only for machines that genuinely cannot run Windows 11 and cannot be replaced before the deadline. Microsoft frames it the same way in its lifecycle FAQ: a last resort paid option, a temporary bridge, not a long term solution.
Two server dates worth separating
The server items on the list are not the same kind of event, and conflating them wastes a maintenance window.
Windows Server 2012 and 2012 R2 reach the end of Extended Security Update Year 3. That is terminal. ESU for those releases was a three year program and October 13 is the last day of the third year. There is no Year 4 and no further paid option outside Azure, where Microsoft continues to provide updates for 2012 and 2012 R2 virtual machines at no additional cost. If a 2012 R2 box is still doing something important in an association’s server closet, October 13 is the date after which nothing more is coming for it, ever.
Windows Server 2022 moves from mainstream to extended support, which is a phase change rather than an ending. Security updates continue. What stops is non-security updates, feature work and design change requests. Nothing needs to happen that week. It belongs on a roadmap, not a runbook.
Pro Education is not Education
This one is a trap specifically for schools and universities, and it is easy to walk into.
Microsoft’s servicing buckets for Windows 11 24H2 are not "consumer" and "business." They are, per the Windows 11 release information page:
- Home, Pro, Pro Education and Pro for Workstations: end of updates October 13, 2026
- Enterprise, Education and IoT Enterprise: end of updates October 12, 2027
Pro Education sits with Home. It has an October 2026 deadline, not an October 2027 one, despite carrying the word Education in its name. A lab image or a staff laptop batch built on Pro Education in a district or on a campus expires a full year before the Education edition machines next to it.
Anyone maintaining imaging for an institution should check the actual edition string on the gold image rather than the label in the procurement record.
What actually happens to a 24H2 machine on October 14
Nothing dramatic, and that is exactly the problem.
The machine keeps running. Nothing deactivates, nothing locks, no nag screen takes over the desktop. What stops is updates. Microsoft’s release health notification for 24H2 says those devices "will no longer receive fixes for known issues, time zone updates, technical support, or monthly security and preview updates containing protections from the latest security threats."
For most machines the resolution is automatic. Microsoft’s 24H2 status page states it plainly: "Devices running Home and Pro editions of Windows 11, version 24H2 that are not managed by IT departments will receive the Windows 11, version 25H2 update automatically."
That upgrade is low risk. 24H2 to 25H2 is an enablement package inside the same servicing branch, build 26100 to build 26200: small download, one restart. It is nothing like the 23H2 to 24H2 jump.
The dangerous population is the half managed environment. Read that Microsoft sentence carefully. Unmanaged machines get upgraded automatically and stay supported. Managed machines do not, because the policy that defers feature updates also defers this one. An organization with enough policy to block the automatic upgrade but not enough process to deploy 25H2 deliberately ends up with a fleet sitting on 24H2 receiving nothing, quietly, from November onward. That describes a fair number of small nonprofits and association chapter offices that turned on update deferral years ago and never revisited it.
One more thing to know before you pick a target version. Windows 11 26H1 exists, it has a later support date, and it is not where you want to go. Microsoft’s 26H1 documentation says it ships preinstalled on select new devices only, is not offered through Windows Update as an in place upgrade, exists only in Pro and Enterprise, is built on a different Windows core, and that devices running it will not be able to update to the next annual feature update. It is a hardware specific branch, not a step forward. The correct target for a general fleet is 25H2, whose Home and Pro servicing runs to October 12, 2027.
What to do in the next three weeks
The Windows piece mostly handles itself. The rest does not.
Inventory Office before anything else. Find every machine running Office 2021 or Office LTSC 2021. That is the item with no automatic remediation, no forced upgrade and no billing reminder. Decide now whether those seats move to Microsoft 365 or to a later perpetual release, because after October 13 every Outlook on that list is an unpatched mail client.
Check the edition string, not the label. Pro Education expires in 2026. Education expires in 2027. The names are close enough that a spreadsheet built from purchase orders will get this wrong.
Find the half managed machines. Anything with update deferral policy but no deployment process will sit on 24H2 unpatched rather than taking 25H2 automatically. Either remove the deferral or schedule the upgrade.
If you are an education customer paying commercial ESU rates, stop. One dollar per device against sixty one is not a rounding error, and the education pricing covers K-12 and higher education alike. Confirm the procurement channel with your licensing reseller, because Microsoft publishes the price without publishing the agreement type.
If you are a nonprofit, price the TechSoup Windows 11 Pro grant against ESU before buying ESU for anything. Fifty granted licenses go a long way, and ESU only makes sense for hardware that genuinely cannot take Windows 11.
Find your Windows Server 2012 and 2012 R2 boxes, if any survive. October 13 is Year 3 of ESU, and there is no Year 4. After that date there is no paid path to updates outside Azure. That is a terminal date, not a renewal.
Seven dates, one Patch Tuesday. The one that costs somebody a bad November is the one with no invoice attached to it.
Frequently Asked Questions
When is Office 2021 end of support?
October 13, 2026, for both the retail and volume perpetual Office 2021 products and the entire Office LTSC 2021 family, including Office LTSC 2021 for Mac, Project 2021 and Skype for Business LTSC 2021. It is end of support rather than end of servicing, which means the product is finished and there is no newer version within it to move to.
Does Office 2021 stop working on October 14?
No. It keeps opening and saving documents. What stops is security updates. The practical risk sits with Outlook, which parses untrusted content continuously, and with the file parsers in Word and Excel.
When does Windows 10 consumer ESU actually end?
October 12, 2027. A lot of guidance still says October 13, 2026, which was the original one-year end date before Microsoft extended the program in a page edit in late June 2026 with no announcement post.
How much does Windows 10 consumer ESU cost?
It can be free. Microsoft lists three enrollment routes: no additional cost if the PC syncs its settings through Windows Backup, redemption of 1,000 Microsoft Rewards points, or a one time purchase of thirty dollars. One license covers up to ten devices, and the device must be on Windows 10 version 22H2 with an administrator Microsoft account.
How much does commercial Windows 10 ESU cost, and is Year 2 really double?
Microsoft publishes 61 dollars per device for Year 1 and states that the price doubles each consecutive year, which puts Year 2 at 122 and Year 3 at 244. Those last two figures follow from the rule rather than from a published price list.
If I skipped Year 1, can I just buy Year 2?
No. Microsoft’s own wording is that ESUs are cumulative and that buying in Year Two requires paying for Year One as well. Coverage starting October 14, 2026 costs 183 dollars per device, not 122.
Is there a nonprofit discount on ESU?
No published one. Microsoft’s nonprofit offers page and FAQ do not mention Extended Security Updates at all. Education customers pay 1, 2 and 4 dollars for the three years; nonprofits pay the commercial 61, 122 and 244. TechSoup distributes all three ESU years, and its admin fee is worth getting directly from TechSoup.
Which Windows 11 editions actually expire on October 13, 2026?
Home, Pro, Pro Education and Pro for Workstations. Enterprise, Education and IoT Enterprise run to October 12, 2027. Pro Education expiring with Home rather than with Education is the detail most likely to catch a school or university.
What version should a general Windows 11 fleet be on?
Version 25H2, whose Home and Pro servicing runs to October 12, 2027. Windows 11 26H1 has a later date but ships only preinstalled on select new devices, is Pro and Enterprise only, sits on a different Windows core, and cannot update to the next annual feature update. It is not an upgrade target.
Will unmanaged machines upgrade themselves?
Yes. Microsoft states that Home and Pro devices on 24H2 that are not managed by an IT department receive 25H2 automatically. Managed machines with feature update deferral will not, and those are the ones that end up unpatched.
Why do two Microsoft pages give different dates?
The product lifecycle tables at learn.microsoft.com render end dates as a timestamp one day after the real date, so October 13 displays as 10/14/2026 6:59:59 AM. The Windows release health dashboard and the end of support index carry the correct date.
