Side hustle tax, sorted in order
Earning on the side changes your tax position the moment you pass £1,000. This guide runs the five calculations that decide what you keep and when you must tell HMRC — from the trading allowance to self-employed tax and VAT.
You sold £3,000 of handmade goods this year. What do you owe?
£1,000
tax-free trading allowance
On top
of your salary
£90,000
VAT threshold
A side hustle isn’t taxed in its own neat bands — it stacks on top of your day job, at your highest rate, and the £1,000 trading allowance is measured on gross income, not profit. Cross it and you must register, even if no tax is due. Each calculator below settles one question — run them in order and you’ll know exactly what you owe and what you must report.
The side hustle path, step by step
Five calculations in the order they arise as your side income grows — check the allowance first, then the tax, then the thresholds that come with scale.
Have you passed the £1,000 trading allowance?
The trading allowance lets you earn £1,000 of gross income tax-free each year. Below it, you owe nothing and need not register. Cross it and you must register for Self Assessment and report the income — measured on total receipts before expenses, not profit. Check where you stand first.
Side Hustle Tax Calculator →How much tax will you pay on the profit?
Once over £1,000, your side profit is taxed at your marginal rate on top of your salary — there’s no second personal allowance. A basic-rate worker keeps about 74p in the pound after Income Tax and Class 4 NI; a higher-rate one closer to 54p. Work out the real figure.
Self-Employed Tax Calculator →How much National Insurance is due?
Self-employed profit attracts Class 4 National Insurance on top of Income Tax — 6% on profit between the lower and upper limits, 2% above. It’s the reason your effective rate is higher than the headline Income Tax band suggests, and it’s easy to forget when budgeting.
Sole Trader NI Calculator →Are you near the VAT threshold?
If your side hustle takes off and taxable turnover passes £90,000 over a rolling 12 months, VAT registration becomes compulsory. Most side hustlers never reach it — but a fast-growing reselling or services business can, and crossing it unnoticed is costly. Track your rolling total.
VAT Threshold Calculator →Do you owe tax on crypto gains?
If your side activity is buying and selling crypto, gains are usually Capital Gains Tax, not Income Tax — a different regime with its own £3,000 allowance. Trading as a business is treated differently again. Work out which applies before you assume the trading allowance covers it.
Crypto Tax Calculator →Why the order matters
The £1,000 allowance comes first because it’s the gatekeeper: below it there’s nothing to calculate and nothing to report. Plenty of people skip this and either panic unnecessarily over a £400 hobby, or miss that their £1,500 of sales already crossed the line.
The tax and National Insurance steps then come before the VAT and crypto questions because most side hustles never reach those thresholds — but everyone over £1,000 owes Income Tax and Class 4 NI. Settle the certain costs first, then check the thresholds that only bite at scale.
What a side hustler keeps per £1 of profit
Because side income stacks on your salary, it’s taxed from the first pound at your highest rate. These are rough take-home figures after Income Tax and Class 4 National Insurance.
| Your tax band | Roughly kept per £1 of profit |
|---|---|
| Basic-rate taxpayer (20% + 6% NI) | ~74p |
| Higher-rate taxpayer (40% + 2% NI) | ~54p |
| Additional-rate taxpayer (45% + 2% NI) | ~53p |
These are approximate — your exact figure depends on total income and whether you claim the £1,000 allowance or actual expenses (whichever is lower, never both). The key point is that there’s no fresh tax-free allowance for the hustle. Run your numbers through the side hustle tax calculator.
Ready to run your own numbers?
Begin with the trading allowance — it decides whether you owe anything at all — then work down the path one calculator at a time.
A side-hustler’s path, worked through
One realistic example, run through the whole sequence, to show how the steps connect in practice.
- Trading allowance. Aisha’s gross sales are £6,000 — well over the £1,000 allowance — so she must register for Self Assessment.
- Tax on profit. As a basic-rate employee, her side profit is taxed at 20% plus 6% Class 4 NI — she keeps roughly 74p per £1 of profit.
- National Insurance. Class 4 NI applies on profit above the threshold — the bit that makes her effective rate higher than the headline 20%.
- VAT. At £6,000 turnover she’s nowhere near the £90,000 VAT threshold, so no action needed — she just tracks it in case the shop scales.
- Crypto check. She also dabbled in crypto; she confirms those gains fall under Capital Gains Tax, separate from the trading allowance, with their own £3,000 exemption.
The takeaway: if Aisha had assumed her hobby was ‘too small to matter’, she’d have missed a registration she legally owed. Checking the £1,000 allowance first told her she was in the system; the rest just sized the bill.
Five mistakes side-hustlers make
The errors that recur among UK side-hustlers — and the ones that cost the most.
Measuring the £1,000 limit on profit, not gross
The trading allowance is tested on gross income before expenses, not profit. Sell £1,500 of goods that cost £600 and you’re over the threshold and must register, even though you made only £900.
Cost: missed registration, penalty risk Fix: test on total gross receiptsAssuming a second tax-free allowance
Your side hustle doesn’t get its own £12,570 personal allowance — your salary used it. Side profit is taxed from the first pound at your top rate. Set aside tax accordingly.
Cost: an unbudgeted January bill Fix: reserve tax at your marginal rateClaiming both the allowance and expenses
You can claim the £1,000 trading allowance or actual expenses, never both. Work it out each way and use whichever leaves less taxable profit.
Cost: a rejected return, more tax Fix: pick the cheaper single methodConfusing personal selling with trading
Selling your own used belongings on Vinted or eBay usually isn’t trading and isn’t taxable, however much it totals. Buying or making things to sell is. Platforms reporting to HMRC is a reporting trigger, not a tax threshold.
Cost: needless worry or missed tax Fix: distinguish clear-outs from tradingForgetting that filing is separate from owing
The duty to register and file kicks in at £1,000 gross, even if no tax is due after expenses. Skipping the return because ‘I owe nothing’ can still trigger late-filing penalties.
Cost: late-filing penalties Fix: file once over the thresholdSide hustle tax questions, answered
How much can I earn from a side hustle before paying tax?
Is the £1,000 limit based on profit or total sales?
Why is my side hustle taxed so highly?
Do I have to tell HMRC if I sell on Vinted or eBay?
Do I pay National Insurance on side hustle income?
When would a side hustle need to register for VAT?
How is crypto taxed if it’s my side hustle?
Do I still need to file if I owe no tax?
Other Calclens guides & tools
How this guide is built
The sequence follows how a side hustle grows — checking the trading allowance, then Income Tax and National Insurance, then the thresholds that only matter at scale — the order an accountant would walk a new self-employed client through.
Every calculator linked here is a free Calclens tool with its own methodology and worked examples. The trading allowance, the VAT threshold, Class 4 National Insurance and crypto rules follow current HMRC and GOV.UK guidance; the individual calculator pages carry the detailed figures and sources.
Definitions and sources: methodology · sources.
Not tax advice. This guide is for general information and links to calculators that produce estimates. Whether income is trading or capital, and the tax due, depends on your circumstances — confirm with a qualified accountant or HMRC before acting.