HM Revenue and Customs (HMRC) has issued a stark reminder to taxpayers across the UK: there is now less than one month to meet a crucial financial deadline. Individuals who fail to submit their online Self Assessment tax return by 11.59pm on 31 January 2026 risk being hit with significant penalties, starting at £300 or more.
Who Needs to File and What's the Deadline?
The imminent deadline applies specifically to those who are required to file their tax return online. The window for paper submissions closed much earlier, on 31 October 2025, and anyone who missed that date is already liable for late filing penalties. The Self Assessment system is mandatory for several groups, including self-employed sole traders who earned over £1,000 in the last tax year, individuals with Capital Gains Tax to pay on profits from selling assets, and partners in a business partnership.
Immediate Risks and How to Protect Yourself
In a direct message on social media platform X, HMRC urged: "There's less than one month to go to file your tax return. File yours today and pay your tax bill ahead of the deadline." The revenue body also highlighted the increased risk of fraud during this period, strongly advising customers to never share their HMRC login details with anyone, including a tax agent.
For those who need to stop Self Assessment for future years, such as individuals now liable for the High Income Child Benefit Charge (HICBC) through PAYE, they must notify HMRC before the current filing deadline. If a return has already been sent, they can opt out from the following tax year.
Key Details for Your 2024-25 Tax Return
HMRC has clarified an important point for this year's submission: the 2025 Winter Fuel Payment, or the Pension Age Winter Heating Payment in Scotland, should not be included on the return for the 2024-25 tax year. These payments, received in Autumn 2025, will instead be accounted for in the 2025-26 tax return, which is due by 31 January 2027.
The core message from HMRC is clear and urgent. With the countdown to 31 January well underway, taxpayers must act now to complete their return, calculate their tax bill, and make payment to avoid costly and entirely preventable penalties.
