HMRC warning as thousands of Brits have just two weeks left to avoid £100 fine

Most people have tax deducted automatically from their wages - but those who work for themselves, or have earned extra untaxed income, will need to fill out a self-assessment form

HMRC self-assessment tax payers have just two weeks left to send their tax return form by post.

October 31 is the deadline for paper self-assessment tax returns - if you send a paper tax return after this date, you'll be hit with a £100 fine. However, if you're worried you won't be able to send your documents in time, you can choose to submit your tax return online instead and the deadline for this is January 31.

The tax returns due imminently are for the 2023/24 tax year. Most people have tax deducted automatically from their wages - but those who work for themselves, or have earned extra untaxed income, will need to fill out a self-assessment form.

If you've chosen a paper tax return, you'll need to send an SA100 and make sure it is received by October 31. You should have already received this form in the post if you've opted for a paper return. If your self-assessment doesn't arrive on time, you can still be fined £100 even if you don't have any tax to pay.

You must register for self-assessment through the HMRC website if this is your first time filling in a self-assessment, and the deadline for doing this was technically October 5. It can then take a further ten days working days for you to receive your reference number.

If 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. If you still haven't filed your self-assessment after three months, you’re charged additional fines of £10 a day, up to a maximum of £900.

After six months, you'll get a further penalty of 5% of the tax owed or £300, whichever is greater, and you'll pay the same again after 12 months if you still haven't filed. You will also be charged additional amounts for paying your tax bill late – the deadline for which is also January 31.

You'll be charged 5% of any tax unpaid after 30 days, six months and 12 months. Trusha Shah, Tax Manager at accountancy firm HW Fisher, said: “Last year 96% of people chose to complete their self-assessment tax return online. This means that while an overwhelming majority prefer to do their returns digitally, there are still some individuals who prefer to complete their return via post.

“ If you are planning to complete your tax return by post, remember that the October 31st deadline is the date by which HMRC needs to receive all necessary paperwork – not the last day that you can send your return off in the post. If you don’t think you will have enough time, don’t fear – you can still complete your return online, for which the deadline is the 31st of January 2025.” You may need to fill out a self-assessment form if:

• Your self-employment income was more than £1,000
• Your income from renting out property was more than £2,500
• You earned more than £2,500 in untaxed income
• Your income from savings or investments was £10,000 or more before tax
• You need to pay Capital Gains Tax on profits from selling things like shares or a second home
• You’re a director of a company (unless it was a non-profit organisation)
• Your income, or that of your partner, was over £60,000 and you’re claiming Child Benefit
• You have income from abroad you need to pay tax on
• Your taxable income was over £100,000
• You’re a trustee of a trust or registered pension scheme
• Your state pension was more than your personal allowance, and your only source of income