Class 4 National Insurance is the main National Insurance that self-employed sole traders and partners pay on their profits. As of October 2026, for the 2026 to 2027 tax year, you pay 6% on profits over £12,570 up to £50,270 and 2% on profits above £50,270, and most people pay it through Self Assessment along with their income tax.
If your profits are £12,570 or less, there's no Class 4 to pay. Class 2 has also changed: if your profits are £7,105 or more, Class 2 contributions are treated as paid to protect your National Insurance record, so you don't pay them at all.
Self-employed National Insurance rates for 2026 to 2027
| Your yearly profits | Class 4 | Class 2 |
|---|---|---|
| Less than £7,105 | Nothing | Nothing to pay, but you can choose voluntary Class 2 at £3.65 a week |
| £7,105 to £12,570 | Nothing | Treated as paid, so your record is protected without paying |
| Over £12,570 up to £50,270 | 6% of the profit in this band | Treated as paid |
| Over £50,270 | 6% of the band up to £50,270, plus 2% on everything above | Treated as paid |
Profits mean your self-employed income minus your expenses. So the allowable expenses you claim cut your Class 4 bill as well as your income tax. In practice that's 6p of every pound of profit in the main band, and 2p above it.
How you pay Class 4
Most people pay Class 2 and Class 4 through Self Assessment, so it's part of the same bill as your income tax. That means it's also part of your payments on account. GOV.UK says payments on account are payments towards your next tax bill, including Class 4 National Insurance if you're self-employed.
| Payment | Due by midnight on |
|---|---|
| Balancing payment for the last tax year, plus first payment on account | 31 January |
| Second payment on account | 31 July |
Each payment on account is usually half of the tax you owed the previous year. You don't have to make them if last year's bill was less than £1,000, or if you paid more than 80% of the tax you owed outside Self Assessment. If you earn more than estimated, you make a balancing payment by the next 31 January.
GOV.UK's payments on account example
GOV.UK works one through. Your bill for 2023 to 2024 is £3,000. You'd made 2 payments on account of £900 each (£1,800) based on the year before. So by 31 January 2025 you pay a balancing payment of £1,200 (£3,000 minus £1,800) plus a first payment on account of £1,500 for 2024 to 2025, which is £2,700 in one go, then a second £1,500 on 31 July 2025. Class 4 is inside every one of those figures if you're self-employed.
If you know your bill will be lower than last year, you can ask HMRC to reduce your payments on account, online or by post. If you reduce them too far and end up owing more, you'll pay interest on the difference, so base it on real figures, not hope.
How to get Class 4 right, step by step
- Tell HMRC when you become self-employed as a sole trader or partner. If you haven't yet, see how to register as self-employed in the UK.
- Keep records of income and expenses through the year, because profit is what Class 4 is charged on.
- File your Self Assessment return. The calculation adds Class 4 to your income tax automatically.
- Pay the balancing payment and first payment on account by 31 January, and the second payment on account by 31 July.
- If your profit drops, you can ask HMRC to reduce your payments on account rather than overpaying.
Keep in mind that Class 4 is worked out on your profit for the whole tax year, not month by month, so a slow start to the year doesn't change the rate on the rest. It's the annual total that falls into each band.
Special cases
- Examiners, moderators, invigilators and people who set exam questions pay Special Class 4 National Insurance. The eligibility is the same, but you can't pay it through Self Assessment; you contact the National Insurance office.
- Landlords should check whether their rental is a business before assuming National Insurance applies.
- Ministers of religion without a salary or stipend don't pay National Insurance, though they can pay voluntarily.
- People who invest for themselves or others, not as a business and without a fee or commission, don't pay it either.
Run a limited company instead? our UK corporation tax guide covers that route.
Class 4 vs running a limited company
Class 4 only applies to sole traders and partners. A limited company director isn't self-employed in that sense, so different National Insurance rules apply. If you're weighing the switch, this comparison of sole trader vs limited company is the place to start. National Insurance is one of the numbers that moves, but rarely the only one.
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The verdict
For most sole traders Class 4 is simple: 6% of profit between £12,570 and £50,270, 2% above it, collected with your income tax. The trap is cash flow, not the rate. GOV.UK's own example shows a 31 January payment made up of a balancing payment for the last year plus the first payment on account for the next, so set aside a share of every invoice from day one. And because Class 2 is now treated as paid once you're over £7,105 in profits, there's nothing extra to do to protect your State Pension record.
The self employed contribution is collected through self assessment, and our payments on account guide explains the advance instalments.
Frequently asked questions
What is Class 4 National Insurance?
It's the National Insurance self-employed sole traders and partners pay on their profits, usually through Self Assessment.
What are the Class 4 rates for 2026 to 2027?
6% on profits over £12,570 up to £50,270 and 2% on profits over £50,270.
Do I pay Class 2 National Insurance?
Not if your profits are £7,105 or more, because Class 2 is treated as paid. Below that you can choose to pay voluntary Class 2 at £3.65 a week.
How do I pay Class 4 National Insurance?
Most people pay it through Self Assessment with their income tax, including in payments on account due by 31 January and 31 July.
Is Class 4 included in payments on account?
Yes. GOV.UK says payments on account include Class 4 National Insurance if you're self-employed.
Who has to pay Class 4?
Self-employed sole traders and partners with profits over £12,570 a year. You must tell HMRC when you become self-employed.
