Self-Assessment Tax Return Deadline

self-assessment deadlines

When Should I Submit My Self Assessment Tax Return?

There are two deadlines for submitting your self assessment tax return and they depend on whether you submit

– a paper tax return or

– an online tax return.

The submission deadline for paper tax returns is 31 October following the end of the tax year.

The submission deadline for online tax returns is 31 January following the end of the tax year.


For the tax year ended 5 April 2020, your deadline for a paper tax return is 31 October 2020 and for an online tax return it is 31 January 2021.

When To Pay Self Assessment Tax Bill?

Here the situation gets a bit confusing as there are a few deadlines you need to remember about.

  • 31 January- this is when you have to make your balancing payment together with your first payment on account.
  • 31 July- this is the deadline for your second payment on account.

What Is a Payment On Account For Self-Assessment?

This is an advanced payment that you make towards your self-assessment tax bill. Advance payments are half of your previous year’s tax bill.


If your tax bill for the financial year 6 April 2019 to 5 April 2020 is £5000, your first and second payment on account should be £2500 each.

What Is a Balancing Payment For Self-Assessment?


If you’ve paid £5000 in total through your payments on account but after calculating your actual tax bill for the year it turned out it’s more than that, for example £6000, you have to make a balancing payment of £1000 to cover your whole tax liability.

What If My Payment On Account Is More Than My Tax Bill?

If your tax bill turns out to be less that the total of your two payments on account, HMRC will send you a refund.

Do I Have To Pay HMRC Payment On Account?

You have to make 2 payments on accounts. The only two exceptions when you don’t have to are:

  • your last tax bill was less than £1000.
  • you’ve already paid more than 80% of your tax liability. This could be for example through PAYE.

My First Self-Assessment Tax Return Deadline

Wondering when you should submit your first self-assessment tax return?

Let’s look at an example.


  • You started your business on 5 July 2020.
  • The tax year runs from 6 April to 5 April next year.
  • Your first deadline to submit and pay your self-assessment tax bill is 31 January 2022 for an online tax return (or 31 October 2021 for a paper tax return).
  • 31 January 2022 is also your deadline for making your first payment on account towards your next tax bill.
  • 31 July 2022 is a deadline for your second payment on account.
  • 31 January 2023 is a deadline for your first balancing payment. Here the whole cycle of payments starts again and repeats every year.

If you don’t file your self-assessment tax return and pay your tax bill on time, you will receive a fine from HMRC.

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