Sole Trader Tax Calculator UK
Calculate your Income Tax, Class 4 National Insurance, and net profit as a self-employed sole trader. Updated for 2025/2026.
Ready to Calculate
Enter your income and details on the left to see a detailed breakdown of your tax liability and take-home pay.
Frequently Asked Questions
How to use this calculator
1. Select your calculation period (weekly, monthly, or yearly).
2. Enter your total gross business income/turnover.
3. Enter your total allowable business expenses.
4. The calculator will determine your taxable profit, apply the correct tax bands, and show your final net take-home pay.
Understanding your results
Gross Income: Your total business turnover before expenses.
Expenses: The costs of running your business. These are deducted from your income so you don't pay tax on them.
Taxable Profit: Your income minus your expenses. This is the figure used to calculate your tax.
Income Tax: Calculated using the 2025/2026 UK tax bands after your £12,570 Personal Allowance.
National Insurance: Calculated based on Class 4 NI rates for self-employed individuals (6% on profits between £12,570 and £50,270, and 2% above that).
Common Allowable Expenses
- Office Costs: Stationery, phone bills, internet, and software.
- Travel Costs: Fuel, parking, train or bus fares (but not travel between home and a permanent workplace).
- Clothing: Uniforms or protective clothing needed for your work.
- Staff Costs: Salaries, subcontractor costs, and employer's National Insurance.
- Things you buy to sell: Stock, raw materials, and direct costs of producing goods.
- Financial Costs: Insurance, bank charges, and professional fees (like accountants).
The Essential Guide to Sole Trader Taxes in the UK
Setting up as a sole trader is the simplest way to start a business in the UK. It offers complete control and minimal administrative burden compared to running a limited company. However, as a sole trader, you are personally responsible for your business's debts and, crucially, for calculating and paying your own taxes.
Registering as a Sole Trader
If you earn more than £1,000 from self-employment in a single tax year (6 April to 5 April), you must register for Self Assessment with HMRC. This £1,000 is known as the Trading Allowance. If your income is below this, you generally don't need to declare it or pay tax on it.
You must register by 5 October following the end of the tax year in which you started trading. For example, if you started trading in August 2024, you must register by 5 October 2025.
How Your Tax is Calculated
Unlike an employee whose tax is deducted automatically via PAYE, a sole trader pays tax on their business profits, not their total income. Profit is calculated simply as:
It is vital to keep meticulous records of all your income and expenses throughout the year. If you claim expenses, you cannot also claim the £1,000 Trading Allowance; you must choose whichever is more beneficial.
Income Tax Rates for Sole Traders (2025/2026)
Once you have calculated your taxable profit, you apply the standard UK Income Tax bands. You still receive the standard Personal Allowance of £12,570 (assuming your total income is under £100,000).
- 0%: On profits up to £12,570 (Personal Allowance).
- 20% (Basic Rate): On profits between £12,571 and £50,270.
- 40% (Higher Rate): On profits between £50,271 and £125,140.
- 45% (Additional Rate): On profits over £125,140.
National Insurance Contributions (NICs)
Sole traders also pay National Insurance, but the system is different from employees. Historically, sole traders paid two types of NI: Class 2 and Class 4. However, significant changes were introduced recently:
- Class 2 NICs: From April 2024, the requirement to pay Class 2 NICs was effectively abolished for most self-employed people. If your profits are above £6,725, you are treated as having paid Class 2 to protect your entitlement to the State Pension, but you do not actually have to pay the weekly charge.
- Class 4 NICs: This is the main National Insurance charge for sole traders. For the 2025/2026 tax year, you pay 6% on profits between £12,570 and £50,270, and 2% on profits above £50,270.
Payments on Account
One of the biggest shocks for new sole traders is 'Payments on Account'. If your Self Assessment tax bill is more than £1,000, HMRC requires you to make advance payments towards your next year's tax bill.
These are paid in two instalments: the first on 31 January (alongside your balancing payment for the previous year) and the second on 31 July. Each payment is half of your previous year's tax bill. It is crucial to budget for this, as your first January tax bill can be 50% higher than you expect.