TL;DR: Office 2021 support ends 13 October 2026. Here's why that matters. Office 2021 and Office LTSC 2021 reach end of support on 13 October 2026, with no extension and no paid security updates. Windows Server 2012 and 2012 R2 get their final security update the same day. There is no year four. Publisher has already stopped working for Microsoft 365 subscribers as of 1 October 2026. Windows 10 machines on Extended Security Updates need their Year 2 cover sorted before 13 October. Mid-October is shaping up to be one of the busiest weeks in Microsoft...