HMRC crackdown warning as tax rules could see Brits make ‘costly’ mistake | Personal Finance | Finance
HMRC is cracking down on Brits with a “side hustle“, an expert has warned. The Treasury has reminded those who make some extra cash outside their main job, such as by selling items online, that under UK law, everyone has a trading allowance of £1,000 each tax year. If more than this is earned, you would need to pay a fiscal price.
Peter Watton, a spokesman for OddsMonkey, said casual sellers clearing out wardrobes or garages don’t need to worry, but anyone earning more than the annual threshold from flogging goods or services may need to declare it. Selling personal items worth more than £6,000 in a single sale could also trigger capital gains tax, the expert added.
Mr Watton said: “With the constantly increasing cost of living, we were hardly surprised that Brits are having to take up side hustles in order to earn themselves some extra cash.
“While it is great that Brits are using their passions to earn extra income, it is important to remember to declare any income over £1,000 to ensure you don’t get in trouble with the tax man.”
OddsMonkey says more than 16million people in the UK are now running a “side hustle” and earning hundreds of pounds a month to cope with the cost-of-living crisis.
Research by the firm covering 2025 showed that almost two in five Brits (39%) earn extra income on the side, pulling in an average of £914 a month (£210 a week).
Yet, with millions reportedly failing to declare their earnings, workers planning a side hustle in 2026 have been urged to make sure they stay on the right side of the rules.
The most popular way to earn extra cash is by selling unwanted items, experts say.
Sixty-eight percent sell secondhand goods online via platforms such as Vinted, eBay and Depop, with average earnings being £165 per month.
Other popular cash-raisers include selling crafts (£163), baking goods (£183), renting out a spare room (£241), blogging (£231), and selling beauty products (£249 per month).
HMRC is increasing its focus on additional earnings in 2026, OddsMonkey said, with its specialists warning that “what starts as a harmless hustle could quickly become a costly mistake if the rules aren’t followed”.
