HMRC’s tax deadline is just days away and if you fail to submit and pay in time you could be slapped with an instant £100 fine.
But confusion around what you might be allowed to claim could see you landed with a fine or a bigger bill to pay down the line if you get it wrong.
Self-assessment tax returns are mandatory for self-employed people, but it’s not only the self-employed who are liable to submit a return to HM Revenue and Customs before Sunday, February 1.
Anyone who earned income on the side over £1,000, such as for selling on ebay or running a side hustle, those who made money from renting out property, who sold shares or assets, or who earned over the threshold to repay Child Benefit, must file a return by the end of Saturday too.
According to experts Capital On Tap, searches for ‘allowable expenses for self employed’ has sparked sharply this January, with many people trying to work out what they legally can and can’t claim within HMRC’s rules.
It said: “Search interest in allowable expenses for self-employed spikes sharply as the deadline approaches. In January 2025, the term was searched over 300% more than in summer months, showing that many SMEs [small and medium sized enterprises] only question what they can and can’t claim at the final stage of filing. This last-minute surge increases the risk of rushed or incorrect expense claims when time is limited.”
Rebecca Alford, Chief Financial Officer at Capital on Tap, said: “If you’re unsure whether something is claimable, ask one question: was this cost incurred wholly and exclusively for business?
“Home office costs, phone bills and travel are the most commonly misclaimed. HMRC’s simplified expenses calculator can help sole traders quickly work out what proportion of these costs is allowable, rather than guessing.”
She added: “If you realise something is wrong, you have 12 months to amend your return online. Correcting errors early can reduce penalties and interest, and in many cases avoid an HMRC enquiry altogether.”
Ms Alford also outlined how some expenses can be capital expenses, not regular ones, which also changes the calculation. She added: “Laptops, phones, tools and machinery can often be claimed as capital allowances rather than regular expenses, which changes how relief is calculated. Missing this can mean spreading tax relief over years instead of claiming it upfront.”
The deadline for HMRC self-assessment is 11.59pm on Saturday, January 31.