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What is National Insurance?

It builds up your state pension entitlement and helps pay for the NHS and other welfare services.


Employed people have it deducted from their wages or salaries by their employers.


Self-employed people such as sole traders pay National Insurance based on how much profit they make from their business.


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


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.


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)


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


  • Class 2 NICs – payable as a weekly flat rate of £3.05 (up from £3.00 in 2019/20)
  • 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

For the 2020/21 tax year, you will need to pay Class 2 National Insurance (£3.05 per week) if the profit made by your sole trader business is more than £6,475 (up from £6,365 in 2019/20). This amount is known as the ‘Small Profits Threshold’.


The Class 2 rate per week is £3.05, which you need to pay annually to HMRC through the Self Assessment process. So your Self Assessment liability to HMRC includes the Class 2 NIC of £158.60  for the tax year (up from £156.00 in 2019/20).


No National Insurance is payable on any profit up to the Small Profits Threshold. You may, however, wish to make voluntary Class 2 NI contributions


Class 4 NICs

For the 2020/21 tax year, you’ll need to pay Class 4 National Insurance if the profit made by your sole trade business is more than £9,500. This amount is known as the ‘Lower Profits Limit' (up from £8,632 in 2019/20).


If your profits are £9,500 or more a year, you’ll pay Class 4 NICs of:


  • 9% on profits between £9,500 and £50,000
  • 2% on profits over £50,000.


The £50,000 amount is known as the ‘Upper Profits limit’.


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 these. However, if your sole trade business has any employees (not subcontractors, freelancers, or yourself), then you’ll need to run a payroll for them, 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%. This represents another PAYE tax the company has to pay.


Employees rates:

Between £792/month & £4,167                 12%
Over £4,167/month                                  2%


Employer rates:
Between £732/month & £4,167                 13.8%
Over £4,167                                           0%



Voluntary contributions

HMRC allows you to make voluntary National Insurance contributions. However, this is a specialist area and you’ll need to take advice based on your individual circumstances. You’ll need to liaise closely with HMRC to ensure any voluntary contribution made is calculated correctly.


It may be beneficial to make voluntary contributions in order to gain qualifying years towards your state pension entitlement, contribution-based Employment, Support Allowance, Maternity Allowance, and Bereavement Support Payment, even if your profits are below the threshold.