Side Hustle Tax (Trading Allowance)
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.
Data verified · July 2026
Do I need to declare income under £1,000 to HMRC?
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.
Source: 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. · updated 2026
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Everything about Side Hustle Tax (Trading Allowance)
📋Overview+
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.
💡 Best practices
- If your side income is £1,000 or less, use the trading allowance and you don't even need to register with HMRC for it.
- Compare the trading allowance against your actual expenses — use whichever is larger to reduce your taxable profit the most.
- Your side-hustle profit is taxed on top of your employment income, so a well-paid day job can push side income straight into the higher-rate band.
🔢 Concrete example
£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.
📖User guide+
How to use this calculator
- 1
Enter your gross side income and any actual expenses you incurred.
- 2
Enter your main employment income, since it uses up your Personal Allowance and lower tax bands first.
- 3
Choose whether to use the £1,000 trading allowance instead of actual expenses.
- 4
Read the taxable profit, income tax, Class 4 NIC and net side income.
📚Glossary+
- Trading allowance
- A flat £1,000 deduction against gross trading/side income, which can be used instead of actual expenses if it's more beneficial, and makes income up to £1,000 entirely tax-free.
- Class 4 National Insurance
- Self-employment-only NIC charged on trading profit between the Lower and Upper Profits Limits (6% for 2025/26) and above the Upper Profits Limit (2%) — employment income doesn't count towards it.
ℹ️Sources & updates+
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.
FAQ — Side Hustle Tax (Trading Allowance)
Do I need to declare income under £1,000 to HMRC?+
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.
Can I use both the trading allowance and my actual expenses?+
No — you choose whichever gives the bigger deduction: the flat £1,000 trading allowance, or your actual allowable expenses, not both together.