Do you need to tell HMRC about that money you earned?Tax · 5 minute readSelling things online, doing a few jobs for cash, driving for an app. There is a line, it is more generous than people think, and crossing it is not the end of the world.Almost everybody who earns a bit of money on the side asks the same question, usually at eleven at night. The answer is less scary than the worrying, but it does have a real shape.Selling your own old things is not a businessClearing out a wardrobe, selling a games console, shifting a bike you no longer use — that is selling your own possessions, not trading. There is normally no tax to pay on it. It becomes a business when you are buying things in order to sell them on, or making things and selling them, or doing work for other people for money.There is a trading allowanceIf your income from side work is below the trading allowance in a tax year, you generally do not have to declare it. Above that, you do — and if you are doing this regularly with the intention of making money, you should tell HMRC and register as self-employed.Keep the numbers honest about your income, not just your profit: the allowance applies to turnover, and it is easy to mistake one for the other.What you can take off before tax

Things you bought specifically to do the work — materials, stock, equipment used for the business.

Travel that was genuinely for the work, not your normal journey to a job.

A share of costs where something is used partly for work, like your phone or a room at home.

Fees you paid to platforms, if the fee came out of what you earned.

Keep a record from the very first pound. A note of what came in, what went out, and the date, is genuinely all you need to start. Reconstructing a year from bank statements in January is a miserable job you can avoid by spending four minutes a week now.If you get it wrongAlmost everybody gets something wrong the first time, and HMRC is much more interested in people who fix things than people who hide them. Register, declare, correct it if you need to, and carry on.This is a plain-English overview rather than tax advice. For your own situation, get it checked — and if you want the full picture properly explained, that is exactly what our one-day Introduction to Business and Tax course covers.More free articles about money, work and business are at The Next Generation Blog.

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