What Happens if You Miss the Self Assessment Deadline?

HMRC said that over 958,00 taxpayers missed the self assessment deadline due on 31 January 2020. That’s nearly 10% of UK taxpayers who need to file a tax return! So if you are worried that you are going to miss the deadline then you are definitely not alone!

So if you’ve missed filing your tax return, what happens next?

When is the Self Assessment Deadline?

Your tax return for the previous tax year is due on 31 January each year. So if you’re return for the tax year 2019/2020 (6 April 2019 to 5 April 2020) is due by 31 January 2021.

What is the fine for missing the self-assessment deadline?

If you’ve missed the deadline you will receive an automatic £100 fine from HMRC. The late filing penalty is imposed regardless of whether you owe tax or not, so even if your business activities have not resulted in a profit, you must still meet complete a tax return.

Failure to file your tax return within 3 months (the end of April) could result in an additional £10 a day fine for 90 days, bringing the total penalty to £900.

Additional penalties are imposed after 6 and 12 month periods (which may be based on the amount of tax owed). You should expect to be charged interest on any unpaid tax.

Self Assessment Tax Return Penalties

Can I escape the HMRC fine?

HMRC says it will not impose the late filing penalty for people who have a “reasonable excuse”. Beware that HMRC has heard it all before though, and the final decision is at their own discretion.

Fines will typically be waived or suspended if HMRC’s online services pages have not been working though. However, HMRC will not cancel penalties for those who found the Self Assessment online system difficult to use or did not receive the automated official reminder.

To appeal against a fine from HMRC, you’ll need to complete an SA370 form.

What should you do next?

If you have your login details for Self Assessment online, act now to avoid a penalty or more fines being imposed.

Gather all your financial information for the year such as income, expenses, bank interest, any P60s, pension contributions etc. Then go online and complete your tax return.

If you are not yet registered to complete Self Assessment online you will need to register with HMRC and receive an authentication code via post.

Wrapping Up

Self Assessment can be complicated and time-consuming. Filing an accurate return boils down to keeping good records, having your self assessment username and password in a safe place and being aware of the filing deadline well in advance.

Remember that filing your tax return early means your tax bill won’t come as a nasty shock – so give yourself plenty of time and don’t rush it.


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Anita Forrest
About Anita Forrest

Anita Forrest is a Chartered Accountant, spreadsheet geek, money nerd and creator of www.goselfemployed.co - the UK small business finance blog for the self-employed community. Here she shares simple, straight-forward guides to make self-employment topics like taxes, bookkeeping and banking easy to understand.