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  3. What are the key dates I should be aware of when submitting my self-assessment return?

What are the key dates I should be aware of when submitting my self-assessment return?

The below information has been listed in relation to the tax year ending 5th April 2021.



  • 31st July 2021: Second payment on account for 2020/21.

    5 October 2021: register for self-assessment If you’ve never submitted a self-assessment tax return before, you must register by 5 October 2021 in order to submit for the 2020-21 tax year. This will allow you to get your Unique Taxpayer Reference number (UTR) number and activate code in time which you need to file your first return.


  • 31 October 2021: If you send a paper tax return, you must send it back by this date if you want HMRC to collect tax through your tax code, if possible, where you owe less than £3,000. You must have a PAYE source of income to facilitate collection of the underpaid tax. This is the deadline for filing a paper tax return. However, if you receive a notice from HMRC that you must file a tax return after 31 July 2021, you’ll need to send back the completed form within three months of the date issued on the notice. If you miss the deadline for filing your paper tax return, don’t be tempted to try and file it late. You’ll still have time to complete an online tax return instead – as these aren’t due until 31 January. But don’t submit both.

    30 December 2021: If you file your tax return online and also have earnings taxed under PAYE, you can opt to have overdue tax collected via your tax code throughout the following year. However, to be eligible your tax bill must be less than £3,000 and you must file your online return by this date. The advantage of this is that any tax payable would be paid over 12 months from April 2022, rather than a single lump sum by 31 January 2022.

    31 January 2022: The final date for submitting your 2020/21 tax return. Please note that tax returns submitted after the 31 October 2021 must be submitted electronically.
  • 6 April 2022: This is when the new tax year starts.
  1. <New page> What fines are imposed for late submission of self-assessment returns?

1 day late

£100  for one day after deadline.

Up to 3 months late

£10 for each additional day (capped at 90 days) plus £100 initial fine- maximum of £1,000.

     6 months late

Either £300 or 5% of the tax due ( whichever is higher ) on top of the penalties above.

12 months late

An additional £300 fine, or 5% of the tax due, plus the above penalties. In the most serious cases, you may be fined 100% of the tax due.

Updated on 14th April 2021

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