Almost a Third of Self-employed Brits Unsure How Much Tax They Owe

With less than a month to go until the self-assessment deadline, almost a third (31%) of self-employed people in the UK say they are unsure how much tax they owe.

New research among those in self-employment found that one in five (20%) have no idea what their tax bill will be, and are waiting until their return is completed before budgeting for it. A further 15% say they know how much they owe but still need to find the money to pay it by the January deadline.

Mike Parkes, technical director at GoSimpleTax, the self-assessment tax software firm behind the survey, said: “Many self-employed people are still going into January without a clear picture of what they owe or the money set aside to pay it. With household costs remaining high, it’s understandable that people prioritise immediate expenses. The risk is that leaving tax planning too late can result in a large bill that needs to be paid at very short notice.”

The deadline for submitting online self-assessment tax returns and paying any tax owed for the 2024/25 tax year is 31 January 2026.

Despite this, many are leaving their returns until close to the wire. More than a quarter (27%) plan to submit their tax return a month before the deadline, while 8% expect to file just a week beforehand. A small number (3%) say they will submit on the day of the deadline itself.

 Parkes added: “There’s now just over a month left until the self-assessment deadline. Anyone who is self-employed or freelancing and earns more than £1,000 in a tax year needs to file a return by 31 January 2026. You may also need to submit if you are a company director, or if you have income from savings, investments, or capital gains. If you started self-employment during the last tax year, you’ll still need to file, even if you earned less than £1,000.”

He also urged people to take a broad view of their income when assessing whether they need to submit: “The £1,000 threshold covers more than people often realise. That could include income from selling online, renting out a property on Airbnb, paid social media activity, or gains from cryptocurrency. Tax is calculated on your taxable profit, which is your total income minus allowable expenses. If you’re unsure what you earned in the last tax year, it’s worth checking now rather than risking a missed return.”