UK Self Assessment Deadlines 2026–27: Paper vs Online Filing Dates
The Self Assessment deadline for the 2025–26 tax year depends on how you file your UK tax return. Paper returns must reach HMRC by 31 October 2026, but the deadline for online filing and tax payment is 31 January 2027. These dates relate to income earned between 6 April 2025 and 5 April 2026, not the 2026–27 tax year itself. In this guide, we shall learn which deadline applies and how it gives you time to organise your records, prepare your return and avoid late filing penalties. What Are the UK Self Assessment Deadlines for 2026–27? The Self Assessment deadline is entirely dependent on whether you need to register, file a paper return or submit your return online. These dates apply to the 2025–26 tax year, although HMRC may set…