Choosing the Wrong Side Hustle Could Cost Britons More Than £5,000 a Year, New Study Reveals
UNITED KINGBOM / AGILITYPR.NEWS / August 04, 2026 / The difference between choosing the right and wrong side hustle could leave Britons more than £5,000 better off, according to new research from online accountancy firm eAccounts.
The firm's new UK Side Hustle Tax Efficiency Index analysed some of Britain's most popular ways to earn extra income to calculate exactly how much someone would keep after tax if they earned £10,000 during the 2026/27 tax year.
The results reveal that not all side hustles are created equal and choosing incorrectly could result in a surprising tax bill.
While matched betting topped the rankings thanks to its tax-free status under current UK legislation, many of the country's most popular income streams, including selling on Vinted, Facebook Marketplace, Etsy and eBay, could leave higher-rate taxpayers with barely half of what they earn in their own pocket.
According to the analysis, someone earning £10,000 through matched betting would retain the full amount, while the same income generated through online selling could leave additional-rate taxpayers with as little as £3,180 after tax.
Renting out a spare room also ranked highly, with homeowners able to earn up to £7,500 tax free each year through the Government's Rent a Room Scheme before income tax applies. Those considering private tutoring or coaching as a way to earn extra cash when the new school year starts in September will be left with just over half of their earnings after HMRC takes its cut if they are a higher rate taxpayer, but will have less upfront and operating costs.
The UK's Most Tax-Efficient Side Hustles
Matched betting involves gambling. eAccounts does not advise or endorse gambling as a financial strategy. Included here for factual accuracy only as gambling winnings are exempt from income tax under current HMRC rules.
The UK's Least Tax-Efficient Side Hustles
Note: figures reflect the position of an active side hustle business with typical expenses. A casual seller with no meaningful business expenses can instead elect to use the £1,000 trading allowance, which would result in a higher take-home. The full side hustle breakdown including all expenses is available at e-accounts.co.uk/2026/07/17/uk-side-hustle-tax-audit-2026/
Kris Corbisiero, Founder of eAccounts said: "People often choose a side hustle based on what they enjoy or what's trending online, but very few stop to think about how HMRC treats different types of income and that makes all the difference when you’re looking to earn some extra cash.”
The research comes as millions of Britons continue looking for additional income to offset rising household costs.
However, eAccounts warns that many people entering the side hustle economy underestimate both their tax obligations and the amount they may ultimately keep after HMRC has taken its share.
“Two people can each earn exactly £10,000, yet one could take home thousands more than the other simply because of the way that income is taxed,” Corbisiero adds. With online platforms now sharing seller information directly with HMRC, understanding the tax implications before you start has never been more important."
The research also highlights a structural advantage for higher earners doing consistent freelance or consulting work. Operating through a limited company rather than as a sole trader could save a higher-rate taxpayer approximately £1,400 on every £10,000 of net profit, a saving of around £7,000 a year on £50,000 of side hustle income.
The firm says understanding the tax treatment of different income streams before starting a side hustle can help people make more informed financial decisions and avoid unexpected tax bills.
For the full league table with all side hustles and complete expense breakdowns, visit:
https://www.e-accounts.co.uk/2026/07/17/uk-side-hustle-tax-audit-2026/
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