Comment by abrugsch

Until a couple of years ago, Yes(officially). Then HMRC codified what they had effectively been doing already which is to look away for small amounts. There is now officially a £1000 buffer for you to legally earn on the side. You don't need to report it, in fact there isn't even a place to put it on the self assessment forms (unless it's changed this tax year where they've started to be more active on side hustle money - I'll find out when I get round to filling in the SA form - probably mid Jan...)