When is the Self Assessment deadline in 2021?

Updated 27 January 2021

The tax return deadline when filing your online Self Assessment for the tax year ending 5 April 2020 is midnight on 31 January 2021.

There are other important self-employed Self Assessment deadlines too – see them all here.

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January 2020 deadline for 2018-2019 Self Assessment tax returns

If you brought home untaxed income between 6 April 2018 and 5 April 2019 – for example if you were self-employed or earning money from a rental property – the deadline for filing your online tax return for this period was 31 January 2020.

If you’ve missed this filing deadline you’ve probably already received a fine. But the fines keep piling up the longer you delay, so it’s important to file your tax return and pay any tax owed as soon as possible.

If you need a hand, check out our top tax return tips.

Self-employed income earned between April 2019 and April 2020

For untaxed income earned during the 2019-20 tax year, the online deadline for filing your Self Assessment tax return and paying your bill is midnight 31 January 2021.

The government understands that many businesses have had a difficult 2020. If you think you’ll struggle to pay your Self Assessment tax bill in 2021, and owe up to £30,000, you can defer making payment in full until 31 January 2022.

The government has previously said that if you can pay your tax bill, though, you should – not least because interest will be applied to the outstanding balance from 1 February 2021.

Businesses will need to use HMRC’s Time to Pay service online to apply for a deferral. You need to file and know how much you owe before 31 January to set up a plan.

HMRC has also announced that it won't issue late filing penalties in February if you miss the filing deadline, as long as if you file by 28 February. However, you would still need to pay your tax bill by 31 January in this scenario.

Other Self Assessment deadlines

There are several other Self Assessment dates throughout the year to bear in mind. It’s unlikely that all of them will be relevant to you, but understand which ones apply so that you don’t miss any important deadlines.

• 31 July is the deadline for making your second ‘payment on account’ instalment to HMRC. Payment on account applies to you if your Self Assessment tax bill was over £1,000 when you submitted your tax return for the period. It doesn't apply if your tax bill was less than £1,000, or if 80 per cent or more of your tax was deducted at source (for example through your tax code, or because your bank has deducted interest on your savings). Take a look at our payment on account guide if you’re not sure.
• 5 October is the deadline for telling HMRC that you’re self-employed so that they’re aware you need to complete a tax return next year. If you’re already registered as self-employed, there’s no need to do this again. Check out our guide to registering with HMRC for more information.
• 31 October is the Self Assessment deadline for the tax year if you want to file a paper return rather than filing online. However, most businesses find it easier to file their tax return online – and under the government’s Making Tax Digital plans, eventually paper filing may not be an option.
• 30 December is the deadline for filing your online tax return if you want the tax owed to be collected through PAYE via your tax code. This is only an option if you have some income that’s already taxed through PAYE (as in, you’re employed as well as self-employed), and if your Self Assessment tax bill is below £3,000. See our article on tax codes for more information.

Self-employed income earned between April 2020 and April 2021

If you continue earning untaxed income from 6 April 2020, this will fall into the tax year 2020-21, which ends on 5 April 2021.

The deadline for filing a 2020-21 Self Assessment tax return will be midnight on 31 January 2022, although keep an eye on Making Tax Digital announcements in case there are any updates.

Although 2022 may sound like a long way off, it’s a good idea to start thinking about your tax return as soon as you start earning the money. For example:

• consider opening a business bank account to keep business and personal finances separate
• keep all your receipts for tax deductible expenses
• use an app or a spreadsheet to keep track of your income, which should make everything much easier when it comes to filing your tax return

Still feeling confused about Self Assessment dates and deadlines? Ask any questions in the comments.