More than 6.36 million taxpayers have already submitted their 2024 to 2025 return, leaving almost 5.65 million yet to file. Anyone who misses the deadline risks an initial £100 late filing penalty.

Across New Year's Eve and New Year's Day, 54,053 people filed their return. That included 342 customers who submitted in the last hour of 2025. On New Year's Eve, the busiest hour was 11:00 to 11:59 when 3,927 returns were sent, while on New Year's Day 19,789 customers filed, with a peak between 16:00 and 16:59 as 1,994 returns were completed.

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."

Guidance and online support are available on GOV.UK to help customers complete and submit their return. You can start your return, save it and come back to it before sending. The bill does not have to be paid immediately after filing, but it must be paid by 31 January. The HMRC app offers the easiest way to pay and can send reminders so deadlines are not missed. Details of alternative payment options are also on GOV.UK. Late filing penalties are: an initial £100 fixed penalty (even if no tax is due or the tax is paid on time); after three months, daily penalties of £10 per day up to a maximum of £900; after six months, a further penalty of 5% of the tax due or £300 (whichever is greater); and after 12 months, another 5% or £300 (whichever is greater). Late payment penalties of 5% apply to unpaid tax at 30 days, six months and 12 months, with interest charged on overdue amounts.

Anyone who cannot meet the deadline should contact HMRC before 31 January. HMRC will treat customers with reasonable excuses fairly.

People who complete a tax return solely to pay the High Income Child Benefit Charge (HICBC) can opt out and have it collected through PAYE using the new PAYE digital service. Eligible customers need to notify HMRC to stop Self Assessment before the filing deadline. If a return has already been sent, they can stop from the following tax year and HMRC will amend their tax code so HICBC is collected through PAYE.

Customers do not need to include their 2025 Winter Fuel Payment (or Pension Age Winter Heating Payment in Scotland) in their 2024 to 2025 return. Payments received in autumn 2025 will be recovered via the 2025 to 2026 return due by 31 January 2027.

Self Assessment customers are at higher risk of scams. Never share HMRC login details with anyone, including a tax agent. Advice on spotting and reporting HMRC-related scams is available on GOV.UK.