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National Insurance is great. It builds up your state pension entitlement and helps pay for the NHS and other welfare services. Self-employed people who are sole traders pay National Insurance based on how much profit they make from their business. 

Unlike income tax, National Insurance is only payable by people who are aged 16 years or over, and are below the state pension retirement age.

When you’re employed, either through your own limited company as a director, or more commonly as an employee of a larger company, your employment taxes are deducted at source (i.e. before it reaches your pay packet) through HMRC’s Pay As You Earn (PAYE) system. 

Limited company directors often choose to pay themselves a lower tax-efficient salary meaning they pay little or no National Insurance and take most of their income through dividends.

When you’re self-employed as a sole trader, you have to complete a Self Assessment to let HMRC know about your income and they will calculate the Income Tax and National Insurance you need to pay. 

Crunch has a Self Assessment service that can make the process super easy, saving you time and money.

But, first things first, you need to have a National Insurance number.

What is a National Insurance number?

Your National Insurance (NI) number is your personal identifier for the social security system. This identifier ensures that your National Insurance contributions and tax are properly recorded. 

If you don’t think you have one, or you’ve lost it or forgotten it you can go online to to apply for a National Insurance number or for help to find a lost one.

How do I register for National Insurance when I’m self-employed?

When you register as self-employed with HMRC, this covers both Income Tax and National Insurance.

What National Insurance do I pay when I’m self-employed?

As part of the Treasury’s annual budget process, all employment taxes, including the thresholds which affect National Insurance Contributions (NICs) are reviewed. This means from 6th April every year, you need to be aware of the amount of NICs due on the profits made by your sole trader business.

The first thing to understand is that sole traders have different NIC rates to those of PAYE employees (such as limited company directors – who should read our article “How much should I take as a salary“).

There are two main classes of NICs which apply to sole trader profits:

  • Class 2 NICs – payable as a weekly flat rate of £3.45 for 2023/24 tax year (£3.15 for 2022/23 tax year)
  • Class 4 NICs – payable as a percentage of sole trader profits. Both are calculated as part of the annual Self Assessment process.

Class 2 NICs

A major change made by the government in 2022/23 is that no Class 2 NI is payable on any profit up to the NI Lower Profits Threshold (previously, no Class 2 NI was payable up to the Small Profits threshold). This remains the same for the 2023/24 tax year. You may, however, wish to make voluntary Class 2 NI contributions, even if your profits are below the threshold, we'll go into this later in the article.

For the 2022/23 tax year, the government initially determined the Lower Profit Limit as £9,880 from April 2022. This was increased to £12,570 from July 2022 onwards. This has created an annualised figure of £11,908 as the Lower Profits Limit for the 2022/23 tax year. 

This means you will have to pay Class 2 National Insurance if the profit made by your sole trader business is more than £11,908 in the 2022/23 tax year.

For the 2023/24 tax year the lower profit limit will remain at £12,570.

The Class 2 rate per week is £3.45 for the 2023/24 tax year, which you need to pay annually to HMRC through the Self Assessment process. So your Self Assessment liability to HMRC includes the total Class 2 NIC of £179.40 for the tax year. The equivalent amount was £3.15 per week (total £163.80) for the 2022/23 tax year.

Class 4 NICs

For the 2023/24 tax year, you’ll need to pay Class 4 National Insurance if the profit made by your sole trade business is more than £12,570 (the annualised Lower Profits Limit highlighted above). 

You’ll pay Class 4 NICs of:

  • 9% on profits between £12,570 and £50,270
  • 2% on profits over £50,270.

The £50,270 amount is known as the ‘Upper Profits limit’ for the 2023/24 tax year.

In the 2022/23 tax year, If your profits are £11,908 or more a year, you’ll pay Class 4 NICs of:

  • 9.73% on profits between £11,908 and £50,270
  • 2.73% on profits over £50,270.

The £50,270 amount is known as the ‘Upper Profits limit’ for the 2022/23 tax year.

Class 4 NICs are calculated annually by HMRC as part of your Self Assessment. Your Self Assessment liability will include a calculation based on the amount of profit made by your sole trader business.

For Class 4 NICs, you’ll usually pay the amount due to HMRC every six months as part of your payment on account (31st July each year) and/or your final Self Assessment payment (31st January each year). The payment on account is usually an estimate.

Class 1 (Employer’s) National Insurance Contributions

As a sole trader, you usually don’t have to worry about Class 1 NI, unless you also have a job as an employee. However, if your sole trade business has any employees (not subcontractors, freelancers, or yourself), then you’ll need to run a payroll for your employees, and if they earn more than the National Insurance earnings threshold you’ll need to make employer’s NICs for them as well as making the correct deductions for their employee’s NICs.

The threshold for employer NICs works in the same way as employees. For every salary amount your employee earns above the weekly National Insurance earnings threshold, the employer has to pay NICs at 13.8% for the 2023/24 tax year (14.53% for 2022/23). This represents another PAYE tax your business has to pay.

Read more about current tax rates and thresholds

Voluntary contributions

If you have gaps in your National Insurance records, HMRC allows you to make voluntary contributions. Gaps may occur because you were:

  • self-employed but did not pay contributions because of small profits
  • living abroad.

If either of these circumstances apply to you, then you can choose to pay voluntary Class 2 or Class 3 contributions. 

If gaps may have occurred because you were: 

  • employed but had low earnings (earning under £123 a week and not eligible for National Insurance credits)
  • unemployed and were not claiming benefits

you can choose to make voluntary Class 3 National Insurance contributions which are £17.45 a week for the 2023/24 tax year, or £15.85 a week for the 2022/23 tax year. However, this is a specialist area and you’ll need to take advice based on your individual circumstances.

It may be beneficial to make voluntary contributions in order to gain qualifying years towards your state pension entitlement, or if you are entitled to contribution-based Employment and Support Allowance, Maternity Allowance, and Bereavement Support Payment. As mentioned, this can be a complex area and you should take specialist advice.

If you’re eligible to make a voluntary contribution towards your National Insurance record, you’ll need to contact HMRC to ensure any amount you pay is calculated correctly.

Need accounting help?

With a genuinely user-friendly accounting system like Crunch, you’ll ultimately save yourself time.

Getting the most up-to-date information on your company accounts can be very difficult if your records and filings are all manual and not online. Instead of needing to ask your accountant to collect and put together the required data, or having to do it yourself, with Crunch you can see it all in real-time.

Speak to an accounting expert

If you're unsure what level of support you need, our friendly team are on hand to help you pick the right package for you.
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Jake Smith
Content Strategy Manager
Updated on
March 24, 2023

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