Clock ticking for self-assessment tax returns

With the 31 January deadline fast approaching, around 5.65 million people are still yet to file their self-assessment tax return, HM Revenue & Customs (HMRC) has warned.

Anyone who misses the cut-off could be hit with an initial £100 late filing penalty, with additional charges possible after that.

According to data from HMRC, 6.36 million individuals submitted their return at least a month ahead of the deadline. Many even chose to complete theirs over the festive period with 37,435 customers filing their Self Assessment tax returns between Christmas Eve and Boxing Day, with our very own Marketing Director being one of those who did theirs on Boxing Day!  

Between 11am and 12pm on New Year’s Eve was the most popular time to file, with 3,927 returns submitted during that hour. Meanwhile, 19,789 people swapped the usual New Year’s Day walk or TV marathon for sorting their tax return instead.

In total, 54,053 taxpayers submitted their 2024/2025 return on 31 December and 1 January, including 342 people who filed in the final hour of 2025.

Myrtle Lloyd, HMRC’s chief customer officer, said: “New Year is a great time to start afresh. What better way than to ensure your tax affairs are in order for another year than completing your tax return.”

“If you have yet to start, the clock is ticking, go to GOV.UK and start today.”

HMRC is urging anyone who will struggle to meet the deadline to get in touch before 31 January. Those with a reasonable excuse will be treated fairly, it said.

What is Self-Assessment?

Self-Assessment is the process you go through each year where you complete a tax return and declare your income, capital gains and any other income during that tax year to HMRC, outside of income tax that is normally deducted from your wage or pension.  

Although most commonly done by those who are self-employed, anyone who has other income outside what is normally deducted from your wages and pension, need to complete a self-assessment form – which can be paper based or digital. Although you will need a HMRC Gateway account to file your tax return digitally – so do allow time to set that up 

Irrespective of employment status, if you have received any untaxed income before the deadline of that tax year, you may need to complete a tax return. Even if that income comes from eBay, Etsy or similar enterprises.

When you need to submit a tax return

This current tax year ends on 5 April 2026 and all tax returns for this year will need to be completed by 31st January 2027.

Normally, you must tell HMRC by 5 October if you need to complete a tax return and have not sent one before. Then there are different deadlines for different types of tax returns.

If you’re doing a paper tax return, you needed to submit it by midnight 31 October 2026. HMRC must receive a paper tax return by 31 January if you’re a trustee of a registered pension scheme or a non-resident company.  

If you’re doing an online tax return, you must submit it by midnight 31 January 2027, and if you want HMRC to automatically collect the tax you owe from your wages and pension, then you needed to submit your online tax return by 30 December 2026.

In all cases you need to pay the tax you owe by midnight 31 January 2027.  

If you’re interested in finding out more about how we can help you build a tax efficient portfolio, making best use of allowances available to you whilst ensuring your money is working hard, Why not give us a call on 0333 323 9065 or book a free non-committal initial consultation with a member of our team.

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This article is intended for general information only, it does not constitute individual advice and should not be used to inform financial decisions.  

The Financial Conduct Authority (FCA) does not regulate tax or trust advice.