HMRC says 12 million people have 100 days left to file their Self Assessment return
The online deadline for the 2025 to 2026 tax year is 31 January 2027, but paper returns must arrive by 31 October this year.
About 12 million people are expected to file a Self Assessment tax return for the 2025 to 2026 tax year, and HMRC has reminded them that 100 days now remain before the online deadline of 31 January 2027. That is also the date by which any tax owed must be paid.
The earlier deadline is the one more likely to catch people out. Anyone sending a paper return has until 31 October 2026, which is next Saturday.
Who has to file
Self Assessment is mainly for people with income that is not taxed at source through PAYE. That typically includes the self-employed, landlords, people with significant savings or investment income and company directors. HMRC's online checker on GOV.UK tells you whether you need to file. Newcomers have to register first and wait for a Unique Taxpayer Reference to arrive before they can submit a return, so leaving it late carries a real risk.
People who no longer need to file can tell HMRC online, which stops reminder letters and late filing penalties from building up.
Changes on this year's return
Some figures will be filled in for you this time. Around 300,000 people who pay the High Income Child Benefit Charge through Self Assessment will see their Child Benefit details already on the return. Some of them may instead be able to pay the charge monthly through their salary, using HMRC's PAYE digital service, which adjusts their tax code.
The Winter Fuel Payment is now recovered from people with a total income above £35,000, and for those in Self Assessment it is collected through the tax bill. Online returns will show the payment where possible, including the Pension Age Winter Heating Payment in Scotland. Paper filers must enter it themselves.
HMRC also reminds people that gains on cryptoassets above the £3,000 annual Capital Gains Tax allowance must be declared.
Anyone signed up to Making Tax Digital for Income Tax still files this return in the normal way and pays by 31 January.
Why filing early helps
Filing early does not mean paying early. It means you know the bill well before payment is due. PAYE employees who file online by 30 December and owe less than the set limit can usually have the amount collected through their tax code over the following year instead of paying in one go. Anyone who has overpaid gets their refund sooner.
HMRC offers guidance on each section of the return, how-to videos and a digital assistant for common questions. A tax agent, a friend or family member, or a voluntary organisation can also help.
The department is also warning about fraudsters posing as HMRC by text, email and phone. It advises people never to click links in unexpected messages or hand over their sign-in details, and to check any contact against the official list of HMRC phishing examples on GOV.UK.
