100 DAY COUNTDOWN: HMRC urges early Self Assessment submissions ahead of 31 January deadline

More than 3.5 million people have already submitted their Self Assessment tax return for the 2024 to 2025 tax year, with HM Revenue and Customs (HMRC) reminding others that only 100 days remain until the 31 January 2026 deadline.

HMRC is encouraging taxpayers to file early to avoid last-minute stress and to give themselves more time to plan for any tax owed. Those who begin their return early can save progress and return to it later before final submission. Early filing also provides clarity on how much tax is due, allowing for better financial planning.

Last year, over 97% of Self Assessment returns were filed online. Returns for the current tax year can be completed on GOV.UK, where HMRC provides detailed guidance and support tools.

Anyone unsure about whether they need to file a return can use the Self Assessment checker on GOV.UK. The tool also allows users to register or notify HMRC if they no longer need to complete a return.

Changes to Capital Gains Tax (CGT) need particular attention this year. Those who have sold assets such as shares after 30 October 2024 must account for revised CGT rates. The automatic calculation system will not apply the new rates, meaning some taxpayers will need to manually adjust their figures using the adjustment calculator available on GOV.UK.

The introduction of the High Income Child Benefit Charge (HICBC) PAYE digital service means thousands of claimants who previously filed only to pay the charge can now pay it through their tax code. Eligible customers can call HMRC to de-register from Self Assessment before the deadline. If a return has already been filed, they can de-register for the following year, and HMRC will update their tax code accordingly.

HMRC also confirmed that the 2025 Winter Fuel Payment, or Scotland’s Pension Age Winter Heating Payment, does not need to be declared in this year’s return. Payments received in autumn 2025 will instead be accounted for in the 2025 to 2026 tax return, due by 31 January 2027.

Taxpayers are urged to remain alert to scams and phishing attempts. HMRC advises never to share login details with anyone, including tax agents. Full guidance on avoiding scams can be found on GOV.UK.

Myrtle Lloyd, HMRC’s Chief Customer Officer, said: “With 100 days to the Self Assessment deadline, now is the time to get started. Completing your return now means you know you how much tax you need to pay ahead of the deadline. We are here to help with lots of help and advice, just search ‘file a tax return’ on GOV.UK to find out more.”