When is the Self Assessment deadline for tax year 2018-19?

The tax return deadline when filing your online Self Assessment for the tax year ending 5 April 2019 is midnight on 31 January 2020.

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

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January 2019 deadline for 2017-2018 Self Assessment tax returns

If you brought home untaxed income between 6 April 2017 and 5 April 2018 – 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 2019.

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 2018 and April 2019

For untaxed income earned during the 2018-19 tax year, the online deadline for filing your Self Assessment tax return and paying your bill is midnight 31 January 2020.

Self Assessment deadlines in 2019

Before the next online tax return deadline comes around, there are several other Self Assessment dates in 2019 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 2019 is the deadline for making your second ‘payment on account’ instalment to HMRC. This will only apply to you if you were self-employed during the tax year 2017-18 and you owed tax of over £1,000 when you submitted your tax return for this period. Take a look at our payment on account guide if you’re not sure.
  • 5 October 2019 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 2019 is the Self Assessment deadline for the tax year 2018-19 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 2019 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 (i.e. you’re employed as well as self-employed), and if your Self Assessment tax bill for 2018-19 is below £3,000. See our article on tax codes for more information.

Self-employed income earned between April 2019 and April 2020

If you continue earning untaxed income from 6 April 2019, this will fall into the tax year 2019-20, which ends on 5 April 2020.

The deadline for filing a 2019-20 Self Assessment tax return will be midnight on 31 January 2021, although keep an eye on Making Tax Digital announcements in case there are any updates.

Although 2021 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.

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