The short version: in the UK you can earn up to £1,000 in gross side hustle income in a tax year before you need to tell HMRC anything at all, that’s the trading allowance. Above £1,000 you must register and file a Self Assessment return, but you only pay income tax once your total income, side hustle plus everything else, goes over your personal allowance of £12,570. Whether you owe anything at £1,001 or at £15,000 depends entirely on what else you earn, and that’s the bit most people get badly wrong.
The £1,000 trading allowance, explained
HMRC gives every individual a £1,000 tax-free trading allowance each tax year (6 April to 5 April) against income from self-employment, casual work, or a side hustle. If your gross income from all your side hustles combined is under £1,000, you don’t need to register, you don’t need to file a return, and you don’t owe a penny on it. This isn’t a discount, it’s a full exemption up to that line.
The moment you go over £1,000, though, the rules change completely. You now must register for Self Assessment (by 5 October following the end of the tax year you started earning) and declare the full amount, not just the bit over £1,000. You can then either deduct the £1,000 allowance from your income, or deduct your actual expenses, whichever is bigger. Most people selling a few things on Vinted or doing occasional freelance work are better off just claiming the flat £1,000 allowance rather than keeping receipts.
A quick worked example
Say you made £2,400 last year doing freelance proofreading on top of a full-time job. You declare £2,400, subtract the £1,000 trading allowance, and you’re taxed on £1,400. If you’re a basic rate taxpayer through your main job (meaning your salary already uses up your personal allowance), that £1,400 gets taxed at 20%, so you’d owe £280 in income tax, plus Class 4 National Insurance if your total self-employed profit for the year is over £6,725 (the small profits threshold for 2026/27).
Why the £1,000 figure fools people
Here’s the uncomfortable bit nobody likes admitting: the £1,000 trading allowance has nothing to do with whether you owe tax, it only decides whether you need to register and file. I’ve had three separate clients over the past two years come to me convinced that because they’d read “£1,000 tax-free” somewhere, they were safe up to that amount and then safe again after that because “it’s such a small side income.” That’s not how it works.
Once you’re over £1,000 and filing a return, your side hustle income gets added to everything else you earn that year, your salary, dividends, rental income, all of it, and taxed as one pot against your personal allowance and the tax bands above it. So if you already earn £30,000 in your day job, every pound of side hustle profit above your £1,000 allowance is taxed at 20% straight away, because you’ve already used up your tax-free personal allowance through your salary. There’s no separate “side hustle personal allowance.” People imagine there is. There isn’t.
The client who got the shock
I worked with someone, I’ll call her Sarah because that’s not her name, who’d been buying and reselling vintage furniture on the side for about eighteen months. She was earning roughly £2,000 a year on top of her £34,000 marketing job and thought she was under the radar because “it’s not really a business, it’s a hobby that pays for itself.” Vinted and eBay started sharing seller data with HMRC from January 2024 under new digital platform reporting rules, and in early 2026 she got a nudge letter asking her to check whether she needed to register. She hadn’t, because she hadn’t realised her personal allowance was already gone. She ended up owing £400 in backdated tax plus a £100 late filing penalty, which stung far more than the tax itself would have, because it was entirely avoidable with fifteen minutes of paperwork eighteen months earlier.
That’s the real risk with side hustles now. It’s not that HMRC is hunting small sellers, it’s that platforms are legally required to hand over your sales data, and HMRC then matches it against who’s registered. If you want the full breakdown of what counts as taxable and how HMRC finds out, I’ve covered it in detail in this piece on whether side hustles get taxed.
What determines how much tax you pay
Once you’re above the £1,000 allowance and registered, three things decide your bill:
- Your personal allowance, £12,570 for 2026/27, which is shared across all your income, not given separately per source
- Your total combined income, salary plus side hustle profit plus anything else, which decides which tax band you sit in
- National Insurance, specifically Class 4 NI at 6% on profits between £12,570 and £50,270, and 2% above that, only due if your self-employed profit is over £12,570 for the year
So the honest answer to “how much can I earn before paying tax” depends entirely on whether the side hustle is your only income or sits on top of a job:
- If it’s your only income, you can earn up to £12,570 combined (side hustle plus £1,000 allowance logic folded in) before any income tax is due at all
- If you already have a job using up your personal allowance, every pound over the £1,000 trading allowance is taxed, typically at 20%, from the very first pound
- If you’re a higher rate taxpayer already (over £50,270 total income), your side hustle profit is taxed at 40% above the £1,000 allowance
Registering, deadlines, and what happens
If you go over £1,000, here’s the process, step by step, exactly as I’ve walked clients through it:
- Register for Self Assessment at gov.uk by 5 October following the tax year end in which you started earning over £1,000
- HMRC sends you a Unique Taxpayer Reference (UTR), usually within 10 working days, longer if you’re posting from outside the UK
- File your return online between 6 April and 31 January the following year (paper returns are due earlier, 31 October)
- Pay whatever you owe by 31 January, and if your bill is over £1,000, you’ll also need to make “payments on account” toward next year’s tax, split across January and July
- Keep records of income and expenses for at least five years after the filing deadline, HMRC can ask to see them
That payments on account rule catches people out constantly. If you owe £1,800 in tax for one year, you don’t just pay £1,800, you also pay an advance £900 toward next year in January, and another £900 in July. Your first proper tax bill on a growing side hustle can be double what you expected, purely because of this advance payment system, and nobody warns people about it until they’re staring at the number.
Which side hustles tip you over the threshold fastest
Not all side hustles hit £1,000 at the same speed, and that changes how quickly you need to think about registering. Freelance writing and content work, for instance, can go from zero to £1,000 in a single month with two or three decent clients, whereas casual reselling might take a full year to cross the line. If you’re weighing up options, it’s worth reading through which side hustles make the most money before you start, because the earning speed changes your tax timeline, not just your income.
For anyone starting from scratch, the beginner-friendly ideas tend to sit in that slower-growth bracket at first, which buys you time to get your admin sorted. There’s a solid rundown in this guide to side hustle ideas for complete beginners if you’re not sure where to start, and if you’re specifically weighing options that people swear by online, this look at the side hustles Reddit recommends is worth a read too, since some of the most upvoted ideas are also the ones that cross £1,000 fastest.
Freelance and home-based work push you over quicker than you’d think
If your side hustle is freelance writing, proofreading, or virtual assistant work, the £1,000 threshold can disappear within weeks once you land even one or two regular clients, because freelance rates tend to be higher per hour than reselling or casual gig work. I’ve seen writers go from £0 to £1,500 in their first two months just from one retainer client paying £750 a month. If that’s the direction you’re heading, it’s worth reading how freelance writers find side jobs that boost income, because the faster you earn, the sooner registration becomes urgent rather than optional.
The same applies for parents building something around childcare hours. Home-based work, whether that’s virtual admin, tutoring, or selling handmade goods, often starts slowly and then jumps once word of mouth kicks in, and I’ve watched that happen with stay-at-home parents who assumed they had months before needing to think about tax and then found themselves £400 over the threshold by October. There’s a good starting point in this guide on home based jobs for stay-at-home mums if that’s your situation, it covers realistic timelines alongside the ideas.
What people get wrong most often
The single biggest mistake I see is people treating the £1,000 trading allowance as if it were an annual tax-free bonus that resets the clock each time. It doesn’t work source by source. If you earn £600 reselling clothes and £700 dog walking, that’s £1,300 combined, not two separate pots under £1,000 each. HMRC counts all your miscellaneous self-employment style income together against the one £1,000 allowance, unless the income comes from different structures, like property income, which has its own separate £1,000 allowance.
The second biggest mistake is assuming that because tax is deducted automatically from a salary through PAYE, side hustle income works the same way. It doesn’t. Nobody deducts tax for you. You’re responsible for declaring it, calculating it, and paying it, and the penalties for getting this wrong start at £100 for a late return even if you owe no tax at all, rising the longer you leave it, plus interest on any unpaid tax from the day it was due.
The bit that matters more than the £1,000 figure
If you take one thing from this, take this: the number that decides your tax bill isn’t £1,000, it’s your combined total income for the year against the £12,570 personal allowance and the tax bands above it. The £1,000 figure only tells you when you need to start telling HMRC about the money. Focus your planning on that combined total, keep a simple spreadsheet of every payment in and every expense out from day one, and set aside roughly 20 to 30% of any side hustle profit the moment you cross £1,000, so the January bill never arrives as a surprise. That single habit would have saved Sarah her £100 penalty and a stressful few weeks.
Frequently asked questions
Do I need to pay tax on a side hustle earning under £1,000 a year?
No. If your gross side hustle income is under £1,000 in a tax year, you don’t need to register with HMRC or pay any tax on it, thanks to the trading allowance. This applies whether it’s one side hustle or several combined, as long as the total stays under £1,000.
What happens if my side hustle earns exactly £1,000?
Exactly £1,000 sits right on the trading allowance threshold, so no tax is due, but it’s worth registering anyway once you’re close, because going even a pound over means you must register by 5 October following the end of that tax year, and it’s easier to set this up before you’re over the line than scramble afterwards.
Does my side hustle income get added to my salary for tax purposes?
Yes. HMRC treats all your income together, salary, side hustle profit, dividends, and rental income all count toward the same personal allowance and tax bands. If your salary already uses up your £12,570 personal allowance, your side hustle profit above the £1,000 trading allowance is taxed immediately, usually at 20%.
Can HMRC find out about my side hustle if I don’t tell them?
Increasingly, yes. Since January 2024, platforms including eBay, Vinted, Etsy, Airbnb, and Uber have been legally required to report seller and earner data to HMRC under digital platform reporting rules, and HMRC cross-checks this against Self Assessment records, sending nudge letters to people who appear to be under-declaring.
