Tax Year Dates and Self Assessment Deadlines

Missing HMRC deadlines can result in penalties. So if you are self-employed here are all the tax dates and payment deadlines you need to add to your diary.

Tax Year

The tax year runs from 6 April to 5 April each year. So the tax year 2020/2021 starts 6 April 2020 and ends 5 April 2021.

Tax Year Dates and Payment Deadlines 2020/2021

  • 31 January 2020: Self-assessment tax return for 2018/2019 due for filing,
    1st payment on account for 2019/2020 and
    the balance of any tax, national insurance and student loans for 2018/2020 due for payment.
  • 5 April 2020: End of the 2019/2020 tax year
  • 31 July 2020: 2nd Payment on Account for 2019/2020 due for payment
  • 5 October 2020: Deadline to register as self-employed with HMRC
  • 31 October 2020: Deadline for filing paper self-assessment tax return
  • 30 December 2020: Deadline for filing a self-assessment tax return if you want any tax collected through PAYE (max £3,000)
  • 31 January 2021: Self-assessment tax return for 2019/2020 due for filing, 1st payment on account for 2020/2021 and the balance of any tax, national insurance and student loans for 2020/2021 due for payment.

Deadline for Registering for Self-Assessment

If you haven’t registered with HMRC as self-employed, then you’ll need to do so by 5 October following the end of the tax year you started working for yourself.

So if you started working for yourself on 1 January 2020 you’ll need to register as self-employed by 5 October 2020.

If you aren’t sure whether you need to register then use this list to help you decide.

Self-Assessment Tax Return Deadline

The self-assessment tax return deadline is the 31 January each year. By this date you’ll need to have filled out your tax return online declaring your income for the previous tax year.

So the tax return due by 31 January 2021 will cover all your income for the tax year 6 April 2019 to 5 April 2020.

Most people must complete their tax return online, however there are a small number of exceptions where HMRC will accept a paper version. In this case paper tax returns need to be filed by 31 October.

If you are employed and owe less than £3,000 in tax, then you can arrange for any tax you owe to be collected by your employer who will then pay it to HMRC on your behalf. If you want to arrange this, you’ll need to file you tax return by 30 December. HMRC will then contact your employer with a change of tax code.

Tax Dates and Self Assessment Deadlines for the self-employed
Tax Year Dates and Self-Assessment Deadline for the UK Self-Employed

Tax Payment Deadlines

You’ll need to pay any tax you owe by the 31 January each year, along with filing your tax return. But you are also required to make an advance payment to your following years tax bill on the 31 January and 31 July each year. You’ll pay 50% of your January tax bill each time and then adjust for what you have paid when you file your tax return.

This can hit newly self-employed people hard because they need to pay more tax the first time they file their tax return.

Payments on Account Explained

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Anita Forrest
About Anita Forrest

Anita Forrest is a Chartered Accountant, spreadsheet geek, money nerd and creator of - the UK small business finance blog for the self-employed community. Here she shares simple, straight-forward guides to make self-employment topics like taxes, bookkeeping and banking easy to understand.