UK Side Hustle Tax Calculator 2025/26
Estimate the extra Income Tax and Class 4 National Insurance on trading profit alongside your PAYE salary. Your financial figures stay in this browser.
Income Tax uses England, Wales and Northern Ireland bands. Class 4 NI uses trading profit separately from salary. Scottish taxpayer? Use Scottish rates. Methodology and limitations · Filing deadlines
Calculated estimate
Tax Calculation Results
This estimate used Scottish income tax bands because Scotland is selected.
- Estimated take-home profit
- ~£
- Additional Income Tax
- ~£
- National Insurance
- ~£
| Main Income: | £ |
| Side Hustle Income: | £ |
| Deduction used: | £ |
| Side Hustle Profit: | £ |
| Estimated Additional Income Tax: | ~£ |
| Estimated National Insurance Contributions: | ~£ |
| Estimated Total Additional Tax (Income Tax + NI): | ~£ |
| Estimated Effective Tax Rate (Income Tax + NI): | % |
This estimates additional tax on trading profit, not your total Self Assessment bill. It excludes student loans, pensions, benefits, VAT, loss relief, tailored tax codes and Class 1/Class 4 annual NI maximum adjustments. Class 2 is not added to the bill. Payments on account may affect cash due. Check MTD assessment years and exemptions; this result does not determine eligibility.
How tax on extra trading income works
Income Tax is the difference between tax on your PAYE salary plus trading profit and tax on salary alone. Class 4 National Insurance is calculated separately on trading profit. Your salary does not use up the Class 4 profit threshold.
Expenses or trading allowance?
Enter all relevant gross trading income before costs. Choose actual allowable expenses, or the £1,000 trading allowance after confirming eligibility. There is one trading allowance across relevant side hustles, not one per platform. Never deduct both. Compare allowance and expenses or check allowable costs.
2025/26 registration and filing
This tax year ends 5 April 2026. If required, new entrants normally register by 5 October 2026. The normal paper filing deadline is 31 October 2026 and the online filing and payment deadline is 31 January 2027. Late registration can change the filing deadline without extending the payment deadline. Read filing dates and late-registration guidance.
Payments on account can increase cash due at your first January payment; they are advance payments, not extra tax. Making Tax Digital depends on qualifying income in specified assessment years and exemptions. This calculator does not determine eligibility.
Worked examples using actual expenses
PAYE salary £30,000; trading income £5,000; expenses £500
Trading profit is £4,500. Additional Income Tax is £900 with England, Wales and Northern Ireland rates; Class 4 NI is £0 because trading profit is below £12,570. Scottish Income Tax differs.
PAYE salary £48,000; trading income £12,000; expenses £2,000
Trading profit is £10,000. Additional Income Tax is £3,546 with England, Wales and Northern Ireland rates. Class 4 NI remains £0: a higher salary does not make £10,000 of trading profit liable to Class 4.
Common questions
Is the £1,000 threshold income or profit?
It is gross trading income before costs. Combine relevant side hustles. Selling personal possessions is different from trading.
Does my salary affect self-employed National Insurance?
Class 4 uses self-employed profit bands separately from salary. Combined Class 1 and Class 4 annual maximum adjustments can affect some people and are excluded from this estimate.
Do you send my calculations to analytics?
No. Financial inputs, deductions and results stay in this tab. Optional analytics measures only public page labels and usage events, after consent.
Can I use this for two PAYE jobs?
This tool models PAYE salary plus self-employed trading profit. Two PAYE jobs have different National Insurance and tax-code considerations; use HMRC’s guidance on more than one job.
Choose the guide for your income
2025/26 rates used by this calculator
Standard Personal Allowance: £12,570. It reduces by £1 for every £2 of income above £100,000. Pension and other adjustments are outside this estimate.
| Band | Band width after Personal Allowance | Income Tax rate |
|---|---|---|
| Basic | First £37,700 | 20% |
| Higher | Next £87,440 | 40% |
| Additional | Remaining taxable income | 45% |
Class 4 NI is 6% on annual self-employed profit above £12,570 up to £50,270, then 2% above £50,270. PAYE salary does not consume these profit bands. The estimate does not apply Class 1/Class 4 annual maximum adjustments.
Class 2 is treated as paid at profits of £6,845 or more; below this, voluntary Class 2 is £3.50 per week. It is not included in the calculated bill.
Income Tax rates · Scottish rates · Current and archived NI rates