14 April 20262 min read

When does a side hustle become a business?

Selling your old sofa isn't a business. Buying sofas to sell on probably is. Here's how to tell the difference.

In short

There's no single moment when a hobby turns into a business. HMRC looks at what you're doing and why. If you're regularly selling goods or services with the aim of making a profit, you're probably trading, and trading income is taxable.

How it works

HMRC uses a set of common-sense signals, sometimes called the 'badges of trade'. None decides it on its own, but together they paint a picture:

Profit motive: are you trying to make money, or just cover costs?
Repetition: one sale is different from a steady stream.
What you sell: things you bought or made specifically to sell, rather than your own used belongings.
How you sell: marketing, a shop page, adding value before reselling.
Timing: buying and selling quickly suggests trading rather than investing.

A chain of three questions. Are you selling things you bought or made to sell, or charging for a service? If no, it's probably not trading. Are you doing it regularly, aiming to make a profit? If no, it may still not be trading. Is your income above the trading allowance? If no, you may not need to report it. If yes, you'll need to register for Self Assessment. — A rough guide, not a legal test. HMRC looks at the whole picture.

There's also a small trading allowance: a tax-free amount of gross trading income each tax year. If your total trading income (before costs) stays under it, you usually don't need to tell HMRC. Go over it and you'll normally need to register. You can then either deduct the allowance or your actual expenses, whichever helps more. The amount can change, so check GOV.UK for the current figure.

An example

Leah clears out her wardrobe online and makes a few hundred pounds. That's not trading: she's selling her own used things, usually for less than she paid. Her friend Tom buys trainers in sales and resells them at a markup every week. That looks like trading, even though he thinks of it as a hobby.

Common mistakes

Thinking 'it's only on the side' means it's not taxable. Side income counts the same as main income.
Measuring the allowance against profit. It's based on income before costs.
Forgetting that online platforms may share your sales data with HMRC. See Selling online: what platforms tell HMRC.

Your next step: add up last tax year's side income before costs. If it's above the trading allowance, read Registering for Self Assessment, step by step.

How it works

HMRC uses a set of common-sense signals, sometimes called the 'badges of trade'. None decides it on its own, but together they paint a picture:

Profit motive: are you trying to make money, or just cover costs?

Repetition: one sale is different from a steady stream.

What you sell: things you bought or made specifically to sell, rather than your own used belongings.

How you sell: marketing, a shop page, adding value before reselling.

Timing: buying and selling quickly suggests trading rather than investing.

A rough guide, not a legal test. HMRC looks at the whole picture.

Common mistakes

Thinking 'it's only on the side' means it's not taxable. Side income counts the same as main income.

Measuring the allowance against profit. It's based on income before costs.

Forgetting that online platforms may share your sales data with HMRC. See Selling online: what platforms tell HMRC.

Your next step: add up last tax year's side income before costs. If it's above the trading allowance, read Registering for Self Assessment, step by step.