How much National Insurance will I pay as a sole trader?

National Insurance is a system of contributions paid to qualify for certain benefits including the State Pension.

If you’re self-employed, the amount of National Insurance you pay depends on your annual profits. For example, for the tax year ending 5th April 2027:

• If your profits are more than £12,570, you’ll pay Class 4 National Insurance.
• If your profits are £7,105 or more but no more than £12,570, you won’t pay National Insurance, but you’ll still receive a National Insurance credit towards your State Pension and certain other benefits.
• If your profits are below £7,105, you won’t pay National Insurance automatically, but you can choose to make voluntary contributions to help protect your National Insurance record.

You’ll usually work out whether you need to pay National Insurance when you complete your Self Assessment tax return.

You’ll also need a National Insurance number so HMRC can record your National Insurance contributions and credits correctly

If you need to pay National Insurance, it will be calculated automatically when you complete your Self Assessment tax return. Your Class 4 National Insurance is included in your overall Self Assessment tax bill, so you pay it at the same time as any Income Tax you owe.

The deadline for paying your Self Assessment bill is 31 January following the end of the tax year. For example, any National Insurance due for the 2026/27 tax year must be paid by 31 January 2028.

If your Self Assessment bill is above a certain amount, you may also need to make payments on account towards your next year’s tax bill. These payments are due on:

• 31 January during the tax year
• 31 July following the end of the tax year.

Payments on account are advance payments towards your combined Income Tax and Class 4 National Insurance liability. They are not an extra tax bill because any payments you make are deducted from your final Self Assessment bill.

If your self-employed profits are below the Small Profits Threshold, or you make a loss, you can choose to pay voluntary Class 2 National Insurance contributions. Paying voluntary contributions can help protect your entitlement to the State Pension and certain other state benefits.

For the tax year ending 5th April 2027, voluntary Class 2 contributions are £3.65 a week.

Before deciding whether to pay voluntary contributions, check your National Insurance record to see whether you have any gaps and whether making additional contributions would increase your State Pension entitlement. You can also get a State Pension forecast to see how much State Pension you’re on track to receive.

If you’re unsure whether paying voluntary contributions is right for you, consider seeking advice from a qualified tax adviser.