Compliance dates · 31 October 2026 · UK
Paper Self Assessment returns must reach HMRC by 31 October 2026
Paper Self Assessment returns for the 2025 to 2026 tax year must reach HMRC by 11.59pm on 31 October 2026. The test is arrival, not posting.
The date applies to paper filing only. It sits earlier in the year than the online route, which is the whole reason paper filers carry a separate date. Missing it does not close Self Assessment for the year. It moves the filer onto the online route, which carries its own later deadline.
Paper filers for 2025 to 2026
Sole traders, landlords and directors who file on paper. Anyone who files online is on a different date and is not caught by this one.
Getting the return there in time
- Decide now whether you are filing on paper or online for 2025 to 2026.
- If on paper, allow posting time so the return reaches HMRC before 11.59pm on 31 October 2026.
- Keep proof of what was sent and when.
- If the paper date is going to be missed, switch to the online route and its later date.
- Diarise 31 October 2026 as an arrival date rather than a posting date.
Where the MTD ITSA system fits
Paper filing sits inside the same Self Assessment regime that Making Tax Digital for income tax now governs.
MTD ITSA £750
Making Tax Digital for income tax self assessment, phased from April 2026.
Finance Act provisions · United Kingdom
Verified 19 August 2026.