Understanding Self Assessment and your tax return

Self Assessment tax return deadlines

Guide

You must send your Self Assessment tax return and pay any tax you owe to HM Revenue & Customs (HMRC) on time. There are a number of deadlines for Self Assessment that you must keep in mind.

The last tax year started on 6 April 2024 and ended on 5 April 2025.

Self Assessment deadlines

Self Assessment type Deadline
Register for Self Assessment if you need to complete a tax return and have not sent one before 11:59pm on Sunday 5 October 2025
Paper tax returns 11:59pm on Friday 31 October 2025
Online tax returns 11:59pm on Saturday 31 January 2026
Pay the tax you owe 11:59pm on Saturday 31 January 2026


There is usually a second payment deadline of 31 July if you make advance payments towards your bill, known as payments on account.

If you fail to meet the deadline, you may have to pay a penalty. You can appeal against a penalty if you have a reasonable excuse.

When the deadline is different

Submit your online return by 30 December if you want HMRC to automatically collect tax you owe from your wages and pension. You must be eligible.

HMRC must receive a paper tax return by 31 January if you're a trustee of a registered pension scheme or a non-resident company. You can't send a return online.

HMRC might also email or write to you giving you a different deadline.

Partnership returns if you have a company as a partner

If your partnership’s accounting date is between 1 February and 5 April and one of your partners is a limited company, the deadline for:

  • online returns is 12 months from the accounting date
  • paper returns is 9 months from the accounting date

2023 to 2024 tax year and earlier

The Self Assessment deadline for these tax years has passed. Send your tax return or payment as soon as possible - you’ll have to pay a penalty.