This calculator works out your UK side hustle income tax and Class 4 National Insurance for the 2026/27 tax year. Enter your gross side hustle income, choose between the £1,000 trading allowance or actual expenses, and add your main salary if you have one. The result shows your exact tax breakdown instantly.

UK Side Hustle Tax Calculator 2026/27

UK Side Hustle Tax Calculator

Instantly see your income tax and Class 4 NIC for 2026/27

2026/27 rates Includes Class 4 NIC Trading allowance vs expenses

Your income

Main salary (annual, before tax)

Your PAYE employment income. Leave as 0 if you have no main job. This determines how much personal allowance remains for your side hustle.

Gross side hustle income (annual)

Total amount customers or platforms paid you — before any fees or costs are deducted. Not your profit.

Expense method

Your 2026/27 estimate

Taxable profit

£0

Income tax

£0

Class 4 NIC

£0

Total tax bill

£0

Effective tax rate

Net income kept
£0

Calculation breakdownAmount

Gross side hustle income£0

Less: trading allowance (Option A)−£0

= Taxable profit£0

Personal allowance used by salary£0

Personal allowance remaining for hustle£12,570

Income tax (20% / 40%)£0

Class 4 NIC (6% on profit above threshold)£0

Total tax owed£0

Net income you keep£0

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✓ No tax owed. Your gross income is below £1,000 — the trading allowance covers it entirely. No registration or reporting required.

⚠ Payment on Account may apply. Your tax bill exceeds £1,000. HMRC typically requires a 50% advance payment toward next year’s bill, also due in January. Budget for approximately £0 extra in your first January payment.

How to Use This Calculator?

Gross Side Hustle Income

Enter the total amount paid to you — what your customers or the platforms paid, before any deductions or fees. This is not your profit. If Etsy buyers paid you £1,400 and Etsy kept £180 in fees, your gross income is £1,400.

If your gross income is below £1,000, the trading allowance covers it completely. No tax is owed and no registration is required.

For the full explanation of what counts as gross income, see our guide on how the £1,000 threshold works.

Trading Allowance vs Actual Expenses

The calculator offers two options:

Option A (trading allowance): deducts £1,000 flat from your gross income. No receipts needed. Use this when your actual expenses are less than £1,000.
Option B (actual expenses): enter your total allowable costs. Use this when expenses exceed £1,000. For the full list of what you can and cannot claim, see our guide on the full list of claimable side hustle expenses.

The calculator shows results for both options so you can compare and choose the better one.

Main Salary

If you also have a PAYE salary, enter it here. Your salary determines how much of your personal allowance is already used. For most employed people, the full £12,570 personal allowance is used by their salary — which means side hustle profit is taxed at the marginal rate from the first pound above the trading allowance.

What the Calculator Shows?

Income Tax: The income tax owed on your side hustle profit at your marginal rate.
Class 4 NIC: The Class 4 National Insurance owed on self-employed profits above £12,570. For employed people whose salary already exceeds £12,570, Class 4 NIC applies on side hustle profit from the first pound at 6%.
Total Tax Bill: Income tax plus Class 4 NIC combined.
Net Income: What you keep from your side hustle after tax.
Payment on Account Warning: If your combined tax bill exceeds £1,000 and less than 80% of your income is taxed through PAYE, HMRC may require payments on account — advance payments of 50% of next year’s estimated bill, due in January and July. The calculator flags this when applicable.

Important Notes

This calculator provides estimates for planning purposes. Treat the figures as a reliable guide, not a substitute for filing. The calculator:

Uses 2026/27 income tax rates and Class 4 NIC rates
Assumes standard personal allowance of £12,570 (no adjustments for high income, Marriage Allowance, or blind persons allowance)
Does not account for other income types (savings interest, rental income, dividends) that may affect your marginal rate
Does not calculate Making Tax Digital obligations (applies above £50,000 gross from April 2026)
Does not calculate Payments on Account amounts (shown as a warning only)

For advice specific to your circumstances, consult a qualified UK accountant.

The Trading Allowance Decision — Quick Guide

Use the £1,000 trading allowance (Option A) if your actual side hustle expenses are less than £1,000. Common examples: tutors, freelance writers, online consultants, survey participants.
Use actual expenses (Option B) if your costs exceed £1,000. Common examples: delivery drivers (fuel + insurance), makers and crafters (materials), resellers (stock + postage).

When in doubt: enter your actual expenses in Option B and compare the two results. The calculator shows both. Use whichever gives lower taxable profit.

For the full decision guide, see our article on the £1,000 trading allowance explained.

Calculator rates verified against HMRC guidance as of 13 June 2026.

About Sophia Bennett

An experienced editor with a passion for transforming complex subjects into clear, engaging, and accessible content. Focused on maintaining high editorial standards while ensuring readers receive practical, trustworthy, and timely information.

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