Warning for 5 million UK taxpayers

Millions of taxpayers have less than one month to file their Self Assessment tax return, HMRC warns.

With less than a month to the 31 January deadline, 54,053 customers chose to ring in the New Year by filing their tax return for the 2024 to 2025 tax year on New Year’s Eve and New Year’s Day. The figures show:

342 customers beat the bells by filing their tax return in the last hour of 2025
19,789 missed their traditional New Year’s Day walk or day in front of the TV to file their tax return instead
3,927 people filed between 11am and 11:59am on 31 December – the most popular time to file over the two days.

More than 6.36 million taxpayers have submitted their tax return so far, which leaves almost 5.65 million who still need to complete their Self Assessment. Those who miss the deadline could face an initial late filing penalty of £100.

Customers who are unable to meet the tax return deadline need to tell us before the 31 January. HMRC will treat those with reasonable excuses fairly.

The penalties for late tax returns are:

an initial £100 fixed penalty, which applies even if there is no tax to pay, or if the tax due is paid on time
after 3 months, additional daily penalties of £10 per day, up to a maximum of £900
after 6 months, a further penalty of 5% of the tax due or £300, whichever is greater
after 12 months, another 5% or £300 charge, whichever is greater

There are also additional penalties for late payments of 5% of the tax unpaid at 30 days, 6 months and 12 months. If tax remains unpaid after the deadline, interest will also be charged on the amount owed, in addition to the penalties above.

People who complete a Self Assessment tax return to pay the High Interest Child Benefit Charge (HICBC) can opt out and choose to pay it through their tax code via the new PAYE digital service.

Eligible customers need to notify HMRC to stop Self Assessment before the filing deadline. Where a tax return has already been sent, customers can choose to stop from the following tax year. HMRC will then amend their tax code and they will be registered to pay HICBC through PAYE.

Customers do not need to include their 2025 Winter Fuel Payment, or Pension Age Winter Heating payment in Scotland, on their tax return for the 2024 to 2025 tax year as payments received in Autumn 2025 will be recovered in the 2025 to 2026 tax return, due by 31 January 2027.