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.