Around one million taxpayers missed the deadline for submitting their 2024/25 self assessment tax return, according to HMRC, leaving many facing financial penalties.
HMRC reported that more than 27,000 people submitted their returns during the final hour before the midnight cut-off on 31 January. In total, about 475,722 returns were filed on the final day, contributing to roughly 11.5m submissions overall. Despite extended helpline hours and webchat support over the weekend, a significant number of taxpayers still failed to meet the deadline.
Anyone who missed the deadline automatically receives a £100 fixed penalty. This applies even if no tax is owed or if any tax due was paid on time. Further charges may apply if the return remains outstanding. After three months, taxpayers can face additional daily penalties of £10 per day, capped at £900. After six months, a further penalty of 5% of the outstanding tax or £300, whichever is higher, may be added. The same charge can be applied again after 12 months.
Late payment penalties may also apply, including additional charges of 5% of unpaid tax at 30 days, six months, and 12 months. Interest is also charged on overdue amounts.
Self assessment applies to individuals with income not taxed automatically through PAYE, including those earning more than £1,000 from self-employment, property rental, or other untaxed income streams.
HMRC has confirmed it will review cases where taxpayers have a reasonable excuse for missing the deadline. However, tax specialists generally recommend paying any initial penalties promptly to avoid further charges, even if an appeal is planned.