What Are National Insurance Contributions?

National Insurance contributions are payments made by employees, employers, and the self-employed that fund the UK State Pension and certain benefits. This guide covers all NIC classes, rates, and thresholds.

National Insurance Explained

National Insurance contributions (NICs) are a form of tax paid by workers and employers in the UK. They fund the State Pension, Statutory Sick Pay, Maternity Allowance, and other state benefits. NICs are separate from income tax , although both are collected by HMRC.

Your NIC record determines your entitlement to certain benefits and your State Pension. You generally need 35 qualifying years of National Insurance to receive the full new State Pension.

Classes of National Insurance

There are several classes of NICs, each applying to different groups:

ClassWho PaysHow Collected
Class 1 (employee)Employees earning above the Primary ThresholdDeducted through PAYE
Class 1 (employer)Employers on employee earnings above the Secondary ThresholdPaid by employer alongside PAYE
Class 1AEmployers on benefits in kindAnnual payment to HMRC
Class 1BEmployers on items in a PAYE Settlement AgreementAnnual payment to HMRC
Class 2Self-employed with profits above the Small Profits ThresholdThrough self-assessment
Class 3Voluntary contributions to fill NIC gapsPaid directly to HMRC
Class 4Self-employed with profits above the Lower Profits LimitThrough self-assessment

Class 1: Employee and Employer NICs

Employee Contributions (2024/25)

Earnings BandRate
Up to £242 per week (Primary Threshold)0%
£242.01 to £967 per week (Upper Earnings Limit)8%
Above £967 per week2%

The Primary Threshold aligns with the income tax personal allowance on an annual basis (£12,570). Employees start paying NICs once their earnings exceed this threshold.

Employer Contributions (2024/25)

Earnings BandRate
Up to £175 per week (Secondary Threshold)0%
Above £175 per week13.8%

From April 2025, the employer NIC rate increases to 15% and the Secondary Threshold drops to £96 per week (£5,000 per year).

Employer NICs are an additional cost on top of the employee’s salary. They are a tax-deductible expense for the employer when calculating corporation tax or income tax.

Reduced Thresholds for Certain Employers

Some employers benefit from higher secondary thresholds, meaning they pay no employer NICs until the employee earns more:

CategoryAnnual Threshold
Employees under 21£50,270
Apprentices under 25£50,270
Veterans (first year of civilian employment)£50,270
Freeport and Investment Zone employees£25,000

Class 2 and Class 4: Self-Employed NICs

Self-employed individuals pay two classes of National Insurance through their self-assessment tax return.

Class 2 NICs

  • Flat rate of £3.45 per week (2024/25)
  • Due if profits exceed the Small Profits Threshold of £6,725
  • Provides entitlement to State Pension and certain benefits
  • Can be paid voluntarily if profits are below the threshold

Class 4 NICs (2024/25)

Profits BandRate
Up to £12,570 (Lower Profits Limit)0%
£12,570 to £50,270 (Upper Profits Limit)6%
Above £50,2702%

Class 4 NICs do not count towards benefit entitlement — that comes from Class 2. Class 4 is purely a tax on self-employed profits.

Class 3: Voluntary Contributions

Class 3 NICs are voluntary payments that can fill gaps in your National Insurance record. The rate is £17.45 per week (2024/25). You can usually go back and fill gaps for the previous 6 tax years.

Voluntary contributions are worth considering if:

  • You have gaps in your NIC record that will reduce your State Pension
  • You were living or working abroad
  • You were not working and not claiming benefits
  • You were self-employed with profits below the Small Profits Threshold

Class 1A and 1B: Employer-Only Contributions

Class 1A

Employers pay Class 1A NICs at 13.8% on the value of most benefits in kind provided to employees. These include company cars, private medical insurance, and other taxable perks reported on forms P11D. From April 2025, this rate rises to 15%.

Class 1A is due by 22 July following the tax year (or 19 July for postal payments).

Class 1B

Class 1B NICs apply to items included in a PAYE Settlement Agreement (PSA). A PSA allows employers to settle the tax and NICs on minor, irregular, or impractical benefits on behalf of employees. The rate matches Class 1A at 13.8%.

Employment Allowance

Employers can claim the Employment Allowance to reduce their employer NIC bill by up to £5,000 per year. This is available to businesses with employer NIC liability below £100,000 in the previous tax year, but not to companies where the sole employee is a director.

The allowance is claimed through the Employer Payment Summary (EPS) as part of the PAYE reporting process.

NICs and the State Pension

Your National Insurance record directly affects your State Pension entitlement:

  • New State Pension (for those reaching State Pension age from 6 April 2016): Up to £221.20 per week (2024/25)
  • You need 35 qualifying years for the full amount
  • You need at least 10 qualifying years to get any State Pension

A qualifying year is one in which you:

  • Paid or were treated as having paid enough NICs
  • Received National Insurance credits (for example, while claiming certain benefits or caring for a child under 12)

NICs and IR35

Contractors working through personal service companies must be aware of IR35 rules. If a contract is caught by IR35, the worker must pay employee NICs on deemed employment income, and the fee-payer must pay employer NICs. This significantly increases the total tax burden compared to paying dividends from a limited company.

Directors’ NICs

Company directors have their NICs calculated on an annual basis rather than period by period. This means the annual thresholds and limits apply to total earnings for the year, regardless of how they are paid. Alternatively, employers can choose to operate NICs on a per-period basis using the alternative method.

Record Keeping

You can check your National Insurance record online through your Personal Tax Account on GOV.UK. This shows:

  • How many qualifying years you have
  • Any gaps in your record
  • Whether you can pay voluntary contributions to fill gaps
  • Your projected State Pension amount

Employers must keep NIC records as part of their payroll records for at least 3 years after the end of the tax year, maintaining proper accounting records as required by HMRC.