Deadlines: Self-Assessment Extension 2019/20

Submitting your tax return online has a submission deadline of the 31st of January 2021 for the 2019/20 tax year. In previous tax years, if you are late in submitting your self-assessment tax return HMRC would have issued an immediate £100 penalty. For the 2019/20 tax year, you can submit up to 28th of February 2021 without receiving any late filing penalties.

Late Filing Penalty

Trigger Date Penalty
Missed filing deadline: 28 February 2021 £100
Unfiled after 3 months: deadline 30 April 2021 £10 per day for 90 days
Unfiled after 6 months: deadline 31 July 2021 5% of liability to tax (or £300 if greater)
Unfiled after 12 months: deadline 31 January 2022 Additional 5% of liability to tax (or £300 if greater)

NOTE: Although the initial penalty has been pushed back by a month, the 90-day, 6-month and 12-month late filing penalties remain unchanged and continue to operate as normal.


Payment of tax

Payment of tax is due on the 31st of January 2021 – even if the tax return has been submitted to HMRC after this date, the payment date has been left unchanged. If you had opted to delay making your second payment on account that was due to be paid on the 31st of July 2020, this will also be due for payment on the 31st of January 2021.

If you are late in paying your tax liability to HMRC, HMRC will issue penalties and interest.

Late Payment Penalties

Trigger Date Penalty
Unpaid by midnight 1 April 2021 5% of the unpaid tax
Unpaid by midnight 1 August 2021 Additional 5% of the unpaid tax
Unpaid by midnight 1 February 2022 Additional 5% of the unpaid tax

NOTE: Interest at 2.6% per annum will also begin to accrue on unpaid taxes from 1st of February 2021.


Payment plans

If you are having difficulties paying the tax liability in full by 31st of January 2021, you can set up a ‘Time to Pay installment arrangement’ with HMRC. If you owe up to £30,000 you can do this online without having to contact HMRC (see the below link). You are required to wait 48 hours after the time of submission to set up this arrangement. To make a claim to pay your tax liability by installments online you will need to log into your HMRC online account, if you do not have one of these this will need to be set up before making the claim. The process of setting up an online account is relatively straightforward.

You may also be able to set up a Time to Pay arrangement with HMRC if you are unable to pay any other taxes in full. This lets you spread the cost of your tax bill by paying what you owe in installments. You should contact the Payment Support Service (PSS) that HMRC has set up to make these arrangements.



You can appeal against some penalties if you have a reasonable excuse, for example for your self-assessment tax return or self-assessment tax payments being late. HMRC have confirmed that they will allow the impact of the coronavirus pandemic to be considered in tax penalty appeals for missing some tax obligations (such as payment or filing dates). You must be able to explain how you were affected by coronavirus in your appeal – the return must also be submitted, and payment must also be as soon as possible upon missing the necessary personal tax deadlines.


Staying up to date

The above are developments are constantly changing and we will provide updates as quickly as possible through our various channels.

Our ethos at Infinity has always been that we are not just your accountants, but we are your partners in business and in these difficult times this has never been more important.  We want to assure you all that we are doing everything we can to help you and should you have any question, big or small, please get in touch. We are here to help.

We will be releasing various documents with support and help through various channels.  Please connect with our team on LinkedIn and Twitter using the following links.


Simon Cowie – Manging Director –

Greg Houston – Associate Director –

Mark Rhynas – Tax Manager –

LinkedIn –

Twitter –

Email –