HM Revenue and Customs (HMRC) has issued a tax update urging UK households to begin their Self Assessment tax return well ahead of the 31 January deadline, warning that those who fail to file on time will face a fixed £100 late filing penalty—even if there is no tax to pay.
The update, posted to the government website on Thursday (8 October), applies to taxpayers required to submit a Self Assessment return. For online filers, the deadline is 31 January 2027, while paper returns must be submitted by 11.59pm on 31 October 2026—just weeks away. Regardless of filing method, the deadline to submit the tax bill and pay any tax owed for the tax year is 11.59pm on 31 January, giving households several months to plan and budget.
Why early filing matters
HMRC says more than a quarter (26%) of people experience anxiety when tax or financial deadlines approach, so preparing early can help reduce stress and ensure tax returns are accurate, meaning you aren't paying more tax than necessary. Customers signed up to Making Tax Digital for Income Tax still need to submit their Self Assessment return and pay any tax owed by 31 January 2027.
Self Assessment customers with a PAYE income can file online by 11.59pm on 30 December and have any tax owed collected via their tax code. Filing early also means more time to explore payment options if needed.
Who needs to file
A tax return must be submitted if, during the last tax year (April 6 to April 5), any of the following applied: you were self-employed as a sole trader and earned more than £1,000 (before tax relief); you were a partner in a business partnership; you had to pay Capital Gains Tax when you sold or disposed of something that increased in value; you had to pay the High Income Child Benefit Charge and do not pay it through PAYE; or you are an off-payroll worker repaying a student or postgraduate loan.
You may also need to file if you have untaxed income, such as money from renting out property, tips and commission, savings interest, dividends or foreign income. Households unsure whether they need to complete a return for the 2025 to 2026 tax year can use the Self Assessment checker tool on GOV.UK, where they can also register or notify HMRC if they no longer need to file.
Penalties for late filing
Failing to submit your tax return and pay any tax owed by January 31 will result in a fixed £100 late filing penalty, even if you have no tax to pay. After three months, those who still have not filed will face an additional penalty of £10 per day, up to a maximum of £900. After six months, an additional penalty of 5% of the tax due (or £300, whichever is higher) will be added, and after 12 months, another 5% (or £300) will be added.
Should the tax remain outstanding beyond the deadline, interest will be applied to the amount owed, on top of any additional penalties. HMRC added: "Check the filing deadlines. The deadline for sending a paper return is before the deadline for an online return." You can send your return any time after 5 April, and sending it earlier means you can budget properly and have sufficient time to pay your bill by 31 January. You also have the option to set up a payment plan if you do not think you can pay the full amount owed on time.
