Work out the tax and Class 4 National Insurance on your side-hustle or second income, using the £1,000 trading allowance and your main employment income.
Données vérifiées · July 2026
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Gross side income up to £1,000 a year is covered by the trading allowance and is entirely tax-free — you don't even need to tell HMRC about it. Above that, your side-hustle profit (after deducting the trading allowance or actual expenses, whichever is larger) stacks on top of your main employment income for income tax, and is separately subject to Class 4 National Insurance since employment income doesn't count towards the Class 4 thresholds.
£8,000 side income, £500 actual expenses, £45,000 employment income, using the trading allowance: £7,000 taxable profit, generating both income tax at 40% and Class 4 NIC.
Enter your gross side income and any actual expenses you incurred.
Enter your main employment income, since it uses up your Personal Allowance and lower tax bands first.
Choose whether to use the £1,000 trading allowance instead of actual expenses.
Read the taxable profit, income tax, Class 4 NIC and net side income.
Last data update
July 7, 2026
Sources and references
HMRC — Tax-free allowances on property and trading income (gov.uk/guidance/tax-free-allowances-on-property-and-trading-income); HMRC — Self-employed National Insurance rates; HMRC — Income Tax rates and Personal Allowances, 2025/26.
The data in this calculator is updated regularly to reflect the latest official rates. When in doubt, consult the official sources listed above.
No — gross side income of £1,000 or less, covered by the trading allowance, is completely tax-free and doesn't need to be reported on a Self Assessment return.
No — you choose whichever gives the bigger deduction: the flat £1,000 trading allowance, or your actual allowable expenses, not both together.