Overview

• Daily £10 penalties are now being applied to taxpayers who missed the January 31 self-assessment deadline, potentially adding up to £900 over 90 days.
• In addition to fines, an 8.5% interest rate continues to accrue on outstanding balances, further increasing financial pressure on late filers.
• Taxpayers who fail to file by September 2025 will incur an additional penalty of 5% of the tax due or £300, whichever is higher, with a repeat surcharge at 12 months.
• HMRC allows taxpayers to appeal penalties by citing valid reasons such as illness, bereavement, or technical issues, or to apply for a 'Time to Pay' plan for debts under £30,000.
• With hundreds of thousands of taxpayers still unfiled, experts urge immediate action to avoid escalating penalties and financial strain.