Not every money-making hobby counts as a business for tax purposes. Knowing when a hobby crosses into trading territory is vital to avoid unexpected tax bills. If your side project is growing, it might be time to check your tax position and stay compliant.

For instance, HMRC manuals provide the example of someone who enjoys repairing cars or selling stamps in their spare time. Whilst this might lead to making what’s known as taxable supplies, that alone does not mean the person is operating a business. It all depends on whether the activity passes the “business test”. This is a set of measures that HMRC uses to determine whether there’s a business intention.

Generally, small-scale or infrequent sales from hobbies aren’t considered a business. But in some cases, hobbies can evolve. What starts off as a hobby or side interest might grow over time into something more substantial, and that’s when it could begin to attract tax obligations. In fact, many well-known businesses have started out as hobbies before scaling into full operations.

When deciding whether a hobby has crossed into business territory, it’s also helpful to consider how income tax would apply. The Income Tax Act makes it clear that tax is charged on the profits of any trade, profession, or vocation and there are similar VAT rules.

It is also important to look at any costs that have been incurred and whether these might genuinely relate to a business activity.

Source:HM Revenue & Customs | 28-04-2025

If you are unsure whether income from a hobby or side activity has developed into a taxable business, professional advice can help you assess your position and avoid unexpected tax liabilities. At CIGMA Accounting, we regularly support contractorsonline businessesretailers, and technology companies, helping them understand how HMRC applies business tests and when income becomes subject to tax.

Our experienced accountants work with clients across Hammersmith, including nearby areas such as Brook Green and Ravenscourt Park, providing clear guidance on trading status, allowable expenses, Self‑Assessment registration, and ongoing tax compliance as activities grow.

Speak to our local tax experts today to confirm whether your hobby or side income is now classed as a taxable business.


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CIGMA Accounting
CIGMA Accounting Ltd is a forward-thinking accounting and tax firm based in London, dedicated to delivering high-quality compliance, tax planning, and business advisory services to entrepreneurs, landlords, and growing SMEs. With offices in Wimbledon and Farringdon, we combine local expertise with a tech-driven approach to simplify accounting. Our services include corporation tax filing, VAT compliance, HMRC investigation support, R&D tax credit claims, capital allowances optimisation, and bookkeeping automation. What sets CIGMA apart is our ability to blend traditional accounting rigour with AI-powered systems that reduce errors, save time, and provide real-time financial insights. Our team ensures that every client - from startups to high-net-worth individuals - receives a bespoke solution aligned with their growth goals. Whether you need strategic tax planning, help with HMRC disclosures, or a full outsourced finance function, CIGMA Accounting delivers clarity, compliance, and confidence.