The deadline to complete your self-assessment was 31st January 2023. However, if for any reason you have missed it, don’t panic, here’s what you need to do now.

Our previous blog also provided helpful advice on how to prepare for your self-assessment tax return.

First, understand if you need to complete a Self-Assessment Tax Return

The deadline date refers to the 2021/2022 tax year, which ended on 5th April 2022. You were meant to submit your self-assessment tax return if any of the following applied to you in the 2021/2022 tax year:


  • You were self-employed and your income was more than £1,000.
  • Your income was more than £50,000, and you or your partner claimed child benefit.
  • You earned more than £2,500 from renting out property, or from other untaxed income, such as tips or commission.
  • You earned more than £100,000 in taxable income.
  • You earned £10,000 or more before tax from savings, investments, shares or dividends.
  • You earned income from abroad or lived abroad and had a UK income.
  • You need to pay capital gains tax.
  • You received income from a trust.
  • Your state pension was more than your personal allowance and was your only source of income (unless you started getting your pension on or after 6 April 2016).
  • HMRC has told you that you didn’t pay enough tax last year (and you haven’t already paid up through your tax code or via voluntary payments).
  • You filed a self-assessment tax return last year (even if you didn’t owe any tax). You’ll need to file again this year unless HMRC has already written to you to say you don’t need to.


A quick an easy way to check is by using the Government’s free tool by clicking here.


Have you Registered for Self-Assessment?

Hopefully, if it’s your first time filing a return you have already registered, as the deadline for this was the 5th October 2022. However, if you haven’t then don’t delay in doing so because you won’t be able to skip this step! You will need your reference number to submit your self-assessment.


Deadline for Online Self-Assessment

Will I Incur a Fine?

Unfortunately, the deadline has now passed for submitting your online self-assessment. This means if you have missed it there is an automatic £100 fine payable to HMRC.

This fine will be payable, even if there is no tax to pay.

It is imperative if you know you will have tax to pay that you submit your self-assessment as soon as possible and make your tax payment.

If you are late paying your tax, you will be charged 5% of the unpaid tax after 30 days, 6 months and 12 months.

You will also incur penalties of £10 a day after 3 months, up to a maximum of £900. Then after 6 months you will receive a further penalty of 5% of the tax owed or £300 (whichever is greater), this is then repeated at 12 months.

It is imperative you complete your self-assessment AND pay your tax as soon as possible!

Can I appeal my Late-filing Penalty?

There are certain circumstances where you can appeal your late-filing penalty. These could be a partner or close relative has died, you had a serious illness, or have been hospitalised shortly before the filing deadline.

If you believe you have a valid reason for missing the self-assessment filing deadline, you can appeal your penalty. Before you make the appeal however, you should file your self-assessment tax return within 14 days of the missed deadline.

You must also make your appeal within 30 days of the penalty notice being issued.

I can’t afford to pay the tax, what should I do?

It is important you contact HMRC as soon as possible if you do not think you can afford the tax bill. That way you may be able to avoid additional penalties – if you can come to an arrangement to spread out your payments over time.

However, you will still need a reasonable excuse for not paying this on time.

  • Death of a close relative or partner.
  • Unexpected hospital stay.
  • Serious or life-threatening illness.
  • Issues with HMRC online services.
  • Your computer or software failed.
  • A fire, flood or theft prevented you from completing your tax return.


The most important things you can do now:

  1. Ensure you are registered for completing your self-assessment.
  2. Complete your self-assessment online.
  3. Pay any tax owed.
  4. Pay any penalties or fines incurred.
  5. Contact HMRC as soon as possible if you have any problems with the above.


We hope you have found this blog useful on what to do if you haven’t completed your self-assessment. If you need advice or assistance on your personal or business accounts including Tax and VAT returns, contact our friendly team today.