Self Assessment: What happens if I miss the deadline?, image of coins on a table | Crunch
Picture of crunch software on mobile

Professional Bio Templates & Examples

Create a compelling professional narrative for a proper, attention-grabbing introduction.
Website bios
Speaker intros
Professional Profile

Important Notice: Recent changes have been made to the HMRC policies regarding late filing and late payment penalties for Self Assessment. Please read on for the most current information.

How does it normally work?

The annual deadline for submitting your online Self Assessment and paying any tax owed is midnight on 31st January each year. While most self-employed people these days choose to file their Self Assessments online, it’s still possible to do so the old way – via paper forms.

Be warned though, if you submit a paper tax return, the deadline is earlier and HMRC must receive this by 31st October each year.

If you don’t file your return and pay any tax due on time, you’ll face penalties – and there are potential extra penalties.

So don’t delay submitting before the deadline and pay any tax you owe with whatever information you have available – even if you need to subsequently amend your tax return.


Suspension of late filing tax penalties for the 2020/21 tax year until 28th February 2022

HMRC is waiving late filing and late payment penalties for Self-Assessment taxpayers for one month. This means you can file your Self-Assessment tax return for the 2020/21 tax year and pay any tax due by 28th February 2022 and you won’t receive a penalty.  

HMRC does encourage taxpayers to meet the deadline to file and pay any tax due by 31st January 2022 if they can.

The penalty waivers mean that:

  • anyone who cannot file their return by the 31st January deadline will not receive a late filing penalty if they file online by 28th February 2022
  • anyone who cannot pay their Self Assessment tax bill by 31st January 2022 deadline will not receive a late payment penalty if they pay their tax in full, or set up a Time to Pay arrangement, by 1st April 2022.

Interest will be payable from 1st February, as usual, so it is still better to pay on time if you can.

If you cannot afford to pay your latest bill then you can set up a ‘Time to Pay’ payment plan with HMRC to spread the cost of your latest Self -Assessment bill if all the following apply:

  • you owe £30,000 or less
  • you do not have any other payment plans or debts with HMRC
  • your tax returns are up to date
  • it’s less than 60 days after the payment deadline.

You can choose how much to pay straight away and how much you want to pay each month, including any interest due.

How much is the fine if I miss the Self Assessment filing deadline?

Be aware that penalties for late filing now include an automatic fixed penalty of £100 if your return is up to 3 months late.

If your return is more than 3 months late, additional penalties will apply, including £10 per day for up to 90 days, followed by £300 or 5% of the tax due (whichever is higher) at 6 and 12 months late.

In cases of deliberate withholding of information after more than 12 months, even further penalties may apply.

Can I still submit a Paper Self Assessment?

Yes, you can. If you'd prefer not to submit an online Self Assessment, or you can't, you can still file a paper return, although the HMRC deadline for paper submissions is three months earlier, on the 31st October each year. However, if you miss that, and submit only a paper return after the 31st October deadline, the same penalty regime applies. If you miss the paper deadline, you should submit online to avoid penalties.

Additional fines for late payment

This may sound obvious, but don’t forget that you must also have paid the tax you owe by the 31st January (we’ll be discussing automatic “Time to pay” agreements in just a couple of minutes). If you didn’t pay in time then you’ll face additional penalties.

The penalties for late payment of tax have been specified as follows: 5% of the tax due if 30 days late, an additional 5% of the outstanding tax due if over five months late, and a further 5% of the outstanding tax due if over 11 months late.

30 days late 5% of the tax due
6 months late 5% of the tax due at that date
12 months 5% of the tax due at that date

Upcoming Changes in Penalties (April 2026):

Starting April 2026, a new points-based penalty system for late self-assessment returns and tax payments will be introduced. Under this system, you'll receive a point for every missed submission deadline. Once you reach a certain threshold of points, a £200 penalty will be charged.

For each subsequent late submission, another £200 penalty will be levied without increasing the points total. The thresholds for penalties will vary based on the submission frequency – whether it's annual, quarterly, or monthly.

Don't get caught out by Payment on Account

HMRC runs a system called “payment on account” for those who pay most of their tax through Self Assessment. This can catch many people out, especially if it is their first Self Assessment – as it means that the tax due is often 50% higher than expected. Read more in our article about payment on account.

The government’s ‘Time to Pay’ scheme for Self Assessment tax bills for tax year ended 5th April 2020

As highlighted in our introduction, HMRC has taken action to support businesses as the economy recovers from the coronavirus pandemic. If you need additional time to pay your Self Assessment tax bill, you can use HMRC’s ‘Time to Pay’ service through GOV.UK to set up a direct debit and pay any tax that is owed in monthly instalments as agreed with HMRC.

If you wish to set up your own self-serve ‘Time to Pay’, you must meet the following requirements for the 2020/21 tax year:

  • no outstanding tax returns
  • no other tax debts
  • no other HMRC payments set up
  • your Self Assessment tax bill is between £32 and £30,000
  • it is no more than 60 days since the tax was due for payment.

If you do not meet these requirements, or need longer to pay in full, you may still be able to set up a ‘Time to Pay’ arrangement by calling the HMRC Self Assessment payment helpline on 0300 200 3822 or going online to the “If you cannot pay your tax bill on time” page on the website.

If you set up a ‘Time to Pay’ arrangement, you will have to pay interest on the tax paid late. Interest will be applied to any outstanding balance from 1st February 2022 for tax bills due for the 2020/21 tax year.

Can I escape a Self Assessment fine?

HMRC says it will waive the late-filing penalty for people who have a “reasonable excuse”, although this will be done at officials’ discretion.

You may be able to avoid a penalty if a close relative died shortly before the Self Assessment deadline, if you have been seriously ill, or even if you have experienced serious IT problems. Penalties may also be waived or suspended if you’re unable to file your returns due to issues with HMRC’s online services.

On the other hand, HMRC says it will not waive penalties for those who find the Self Assessment system too difficult to use or who did not receive an official reminder, for example.

If you do wish to appeal against a penalty, you’ll need to fill out what’s called a SA370 form, or you can appeal online.

Avoiding future problems

Registering for Self Assessment is probably the most awkward part of the process. Once you’re registered, filing returns in future should be far more straightforward, providing you keep a note of your username and password for the service.

You must keep your records for at least five years after the 31st January submission deadline of the relevant tax year. HMRC may check your records to make sure you’re paying the right amount of tax.

If you filed your 2020/21 tax return online by 31st January 2022, you must keep your records until at least the end of January 2027.

You can file your return at any time after the tax year ends on 5th April each year.

And remember, filing your Self Assessment return early means the size of your next tax bill won’t come as a shock.

Let Crunch take the pain out of Self Assessments

At Crunch, we’re experts at looking after life’s numbers, so you can trust us to make your Self Assessment as worry-free as it can be. Our expert chartered certified accountants will take care of you, just like we did for over 7,500 clients in the last tax year.

guide cover for "8 great ways accountancy can help your ecommerce business"

Unlock your free ecommerce business guide!

Expert Insights
Actionable Tips
Strategic Advice

To receive our guide on valuable insights into the world of expenses for limited companies please submit your details below.

Please enjoy our guide on 8 Ways Great Accountancy Helps ecommerce Businesses Succeed.

Click below to download our PDF guide.
Oops! Something went wrong while submitting the form.

By submitting you are agreeing to be contacted by Crunch.

Speak to an accounting expert

If you're unsure what level of support you need, our friendly team are on hand to help you pick the right package for you.
Self Assessment tax returns done for you, from just £200 £130+VAT
Take the stress out of Sole Trader Accounting, for just 1%+VAT of your money earned. No monthly subscriptions! With CrunchONE
Get 25% Off Crunch Pro and Premium for the first 3 months!
Share this post
Lucinda Watkinson
Head of Accounting
Updated on
January 18, 2024

Knowledge Hubs

Take control of your accounts, today

Crunch’s effective software package includes being able to talk to an expert client manager and a Chartered Certified Accountant. You can count on Crunch to make you productive and profitable.
Picture of crunch software on mobile

Professional Bio Templates & Examples

Create a compelling professional narrative for a proper, attention-grabbing introduction.
Website bios
Speaker intros
Professional Profile

Unlock Your Free Limited Company Expense Guide!

Expert Insights
Actionable Tips
Strategic Advice

Save your seat! Live e-commerce webinar

Register and soak in the wisdom from top industry leader! June 27, 2024 1:30 PM
Dive into e-commerce basics
Expert industry insights
Practical tips and savvy tricks
Pro Tip
Looking for a dedicated accountant?

Our Enterprise packages offer tailored support for you and your business. You can focus on your business, we'll crunch the numbers.

Pro Tip
Boost your business finances with our Ltd Company packages!

Award-winning software with support from expert accountants

Pro Tip
Take the stress out of Sole Trader Accounting

Just 1%+VAT of your money earned. No monthly subscriptions! With CrunchONE

Pro Tip
Get 50% off your Self Assessment

Get your tax return sorted by experts for only £130+VAT!

Pro Tip
Using cloud-based accountancy software to manage your finances gives any small business a big advantage!

At Crunch we provide affordable cutting-edge, easy-to-use software with real human support from expert chartered accountants. That’s probably why 81% of our clients would recommend Crunch.

Pro Tip
Did you know - you have access to a Chartered Certified accountant for free on our paid subscriptions?

Book a call with our one accountants and get your questions answered. Just £25.50 +VAT for Crunch Free users.

Pro Tip
Get 35% off your Tax Return!

Crunch’s Self Assessment service provides an expert accountant to complete, check, and file your Self Assessment for you for just £130 +VAT.

Pro Tip
Did you know - We have a free plan that is great for sole traders and limited companies?

Why not see for yourself? It’s simple and easy to use and 100% free.