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Self-employed or a high earner? Don't miss the 31 January 2024 self-assessment tax return deadline – or risk a £100 fine and 7.75% interest

If you're one of the millions of taxpayers still to file their online self-assessment tax return or pay the tax due, you've just days left until the deadline. Here's what you need to do to avoid a £100 fine and interest charges of 7.75%.

You have until 11.59pm on Wednesday 31 January 2024 to send HMRC an online tax return for the 2022/2023 tax year, which ended on 5 April 2023. The same deadline also applies to those who need to make payments towards their tax bill.

You must act soon as those who miss the deadlines face fines of at least £100 – plus 7.75% interest on any late tax payments.

As of Tuesday 23 January, some 3.8 million people were yet to file their tax return, while 8.3 million returns had already been submitted, according to the latest available figures from HMRC.

See our Tax and Benefits guides to check you're paying the right tax and to see which benefits you may be entitled to – even some families with an income of £50,000 or more can qualify for help.

Self-employed workers and high earners need to file self-assessment tax returns

Most UK taxpayers have their taxes deducted automatically from their wages, pensions or savings, and won't need to file a tax return. But tax returns are due from individuals or businesses who haven't had tax automatically deducted, or who have earned extra untaxed income.

You'll need to submit a tax return if any of the following applied to you in the 2022/2023 tax year:

  • You were self-employed and your income was more than £1,000.
  • You had multiple sources of income over £1,000.
  • You earned £10,000 or more before tax from savings, investments, shares or dividends.
  • You claimed Child Benefit when you or your partner earned more than £50,000 a year. 
  • 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 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 for the 2021/22 tax 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.
  • You were self-employed and earning less than £1,000 but you still want to pay 'class 2' national insurance contributions voluntarily to protect your entitlement to the state pension and certain benefits. 

If in doubt, use the Government's free tool to check whether you need to file a tax return.

Not yet registered for self-assessment? Do this ASAP

Anyone new to self-assessment needs to register with HMRC first. It's crucial you do this as soon as possible – you need to get a Unique Taxpayer Reference (UTR), and it can take up to 10 working days for you to receive it by post.

Once registered, you may be able to see your UTR sooner on the HMRC app or through your online HMRC account.

The deadline to register was technically 5 October 2023 – and you may now be too late to get your UTR in time to file by 31 January. But either way, you must still register to file your return, so don't delay doing so. 

If it's your first time filing online but you already have a reference number – for example, because you've previously filed a paper return – you should be able to skip this step and just register for the online service.

Head to if you've lost your login details

You'll need to log into your self-assessment account with your Government Gateway ID. If you've forgotten your Government Gateway details, you can retrieve your user ID or reset your password online. If you've never used Government Gateway before, you can register on

If you're signing into your self-assessment account for the first time and have forgotten your UTR, you should be able to find it on previous tax returns or on other documents from HMRC, such as payment reminders. It's also available in your online HMRC account.

If you can't find your UTR, you can phone the self-assessment helpline on 0300 200 3310.

You've missed the deadline for filing a paper return

The deadline for filing paper returns for the 2022/23 tax year was 31 October 2023 – so you must file your return online now to avoid paying a penalty. If you were to file a paper return now you would be fined.

Even if you're not ready to file, pay the tax you're likely to owe to avoid whopping 7.75% interest charges

You also need to pay any tax you owe for the 2022/23 tax year (known as a balancing payment) and make your first payment on account for the 2023/24 tax year by 11.59pm on 31 January 2024. 

Miss this deadline and you'll be charged annual interest of 7.75% on the amount owed. This interest will accrue daily, starting on 1 February. Making a payment towards your tax bill now should prevent that (unless your bill is higher than expected once it comes in). However, you will still have to pay a penalty of at least £100 if you file the return late – more on this below.

You can pay by bank transfer, debit card or cheque. You can also pay at your bank or building society if you have a paying-in slip from HMRC. HMRC accepts money under the Faster Payments system, which allows payments to go through in two hours. However, each bank has a limit on how much you can transfer under Faster Payments. The limits range from £5,000 to £100,000. See each provider's limit.

It's worth noting that, if you submitted your online return by 30 December 2023, and met certain other requirements, HMRC may have automatically collected tax owed from your wages and pension.

You could be hit with a £100 fine if you miss the deadline to file – plus extra penalties and interest

If you miss the 31 January 2024 deadline to file your return, you will be charged a £100 penalty – even if there's no tax to pay. 

Further penalties of £10 a day are then applied after three months, up to a maximum of £900. After six months, you'll get an additional penalty of 5% of the tax, which the return would've shown you owed or £300 (whichever is greater). This is then repeated at 12 months.

There are also extra penalties for paying the tax late – this is charged at 5% of the unpaid tax after 30 days, six months and 12 months. Plus, there's an interest charge of 7.75% on top (as set out above).

The Government provides an online tool for calculating how much you'll need to pay in penalties and interest if you miss the deadlines.

Speak to HMRC urgently if you can't afford to pay the tax

If your bill is correct but you find you can't afford it, contact HMRC as soon as possible as you may be able to avoid late payment penalties by coming to an arrangement to spread your payments over a period of time. (Also use our Tax Code Calculator to ensure you're on the right tax code).

If you don't agree a payment plan in advance and miss the deadline, you'll be charged a penalty – unless you had a reasonable excuse for not paying your tax on time. This is usually something unexpected or outside of your control that stopped you meeting your tax obligation. For example:

  • Your partner or a close relative died shortly before the tax return or payment deadline.
  • You had an unexpected stay in hospital that prevented you from dealing with your tax affairs.
  • You had a serious or life-threatening illness.
  • Your computer or software failed just before or while you were preparing your online return.
  • Issues with HMRC's online services.
  • A fire, flood or theft prevented you from completing your tax return.
  • Postal delays that you could not have predicted.
  • Delays related to a disability or mental illness you have.
  • You were unaware of or misunderstood your legal obligation.
  • You relied on someone else to send your return, and they did not.

You can contact HMRC directly for more info

The Government provides help sheets and video guidance on submitting your tax return.

You can also try HMRC's digital assistant, which can help you find the information you need or connect you with an adviser for a live online chat.

If you'd prefer to speak to someone on the phone, you can call HMRC's helpline on 0300 200 3310. It's open from Monday to Friday between 8am to 6pm. It’s closed on weekends and bank holidays.

Until the start of February, the helpline is only dealing with "priority queries" about paying your bill, completing your 2022/23 return or getting a refund. HMRC says this includes queries that cannot be "easily dealt with online". If your query is about anything else, you’ll be directed back to HMRC’s online services.

You can also get general help from HMRC customer support on X, formerly Twitter.

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