National Insurance (UK)
The UK's social security contribution system where employees and employers pay a percentage of earnings to fund the State Pension, NHS, and welfare benefits.
What Is National Insurance in the UK?
Key Takeaways
- ✓National Insurance Contributions (NICs) are mandatory payments made by employees, employers, and the self-employed to fund the UK's State Pension, NHS, and social security benefits.
- ✓Employee NICs (Class 1 primary) are 8% on earnings between GBP 12,570 and GBP 50,270, and 2% on earnings above GBP 50,270 in 2024/25.
- ✓Employer NICs (Class 1 secondary) are 13.8% on all earnings above GBP 9,100, with no upper limit, making it one of the most significant employment costs in the UK.
- ✓NICs fund qualification for the State Pension (35 years needed for the full amount of GBP 221.20 per week) and contributory benefits like Jobseeker's Allowance.
- ✓Salary sacrifice arrangements can reduce both employee and employer NICs by exchanging gross salary for non-cash benefits like pension contributions, cycle-to-work schemes, and electric vehicles.
National Insurance is the UK's social security contribution system. It's a tax in everything but name, deducted from wages and charged to employers on top of salaries. The money funds the State Pension, the National Health Service (NHS), unemployment benefits, and other welfare programs. The system dates back to the National Insurance Act 1911. Every employed and self-employed person in the UK who earns above certain thresholds must contribute. In return, they build a National Insurance record that determines their eligibility for the State Pension and certain benefits. For HR professionals, National Insurance is one of the largest single employment costs. Employer NICs of 13.8% on earnings above the secondary threshold means a GBP 50,000 salary costs the employer roughly GBP 5,644 in employer NICs alone. Understanding how NICs work, and how legitimate salary sacrifice arrangements can reduce them, is essential for compensation planning.
NIC Classes Explained
National Insurance has several classes, each applying to different types of workers and income.
Class 1 primary: the employee's contribution
This is what employees see deducted from their pay. The primary threshold is GBP 12,570 per year (aligned with the personal income tax allowance since 2022). Earnings up to this level are NIC-free. Between GBP 12,570 and GBP 50,270 (the upper earnings limit), employees pay 8%. Above GBP 50,270, the rate drops to 2%. These rates were reduced in January 2024 (from 12% to 10%) and again in April 2024 (from 10% to 8%) as part of government efforts to reduce the tax burden on workers. The rate changes didn't affect employer NICs.
Class 1 secondary: the employer's cost
Employer NICs start at a lower threshold (GBP 9,100 in 2024/25, called the secondary threshold) and there's no upper limit. The rate is a flat 13.8% on all earnings above GBP 9,100. This means employer NICs keep growing proportionally with salary, unlike employee NICs which drop to 2% above the upper earnings limit. For high earners, employer NICs can be substantial. On a GBP 100,000 salary, employer NICs are approximately GBP 12,544. The October 2024 Autumn Budget announced an increase in employer NICs to 15% from April 2025, along with a reduction in the secondary threshold to GBP 5,000. This represents a significant cost increase for employers.
Class 1A: benefits in kind
When employers provide taxable benefits (company cars, private medical insurance, gym memberships), they pay Class 1A NICs at 13.8% on the taxable value. This is reported and paid annually through the P11D process, not through monthly payroll. Certain benefits are NIC-exempt by statute, including employer pension contributions, childcare vouchers (legacy schemes), cycle-to-work schemes, and workplace parking. Understanding which benefits attract Class 1A and which don't is important for designing tax-efficient benefits packages.
| Class | Who Pays | Rate (2024/25) | What It Funds |
|---|---|---|---|
| Class 1 (Primary) | Employees | 8% (GBP 12,570-50,270), 2% above | State Pension, contributory benefits |
| Class 1 (Secondary) | Employers | 13.8% above GBP 9,100 | NHS and social security system |
| Class 1A | Employers | 13.8% on benefits in kind | Charged on taxable employee benefits |
| Class 2 | Self-employed | GBP 3.45/week (above GBP 12,570 profit) | State Pension qualification |
| Class 3 | Voluntary | GBP 17.45/week | Fill gaps in NI record for pension |
| Class 4 | Self-employed | 6% (GBP 12,570-50,270), 2% above | No specific benefit entitlement |
National Insurance and the State Pension
The primary reason employees care about their NI contributions is the State Pension. Your NI record determines whether you qualify and how much you receive.
How qualifying years work
You need 35 qualifying years for the full new State Pension (GBP 221.20 per week in 2024/25, roughly GBP 11,502 per year). A minimum of 10 qualifying years is needed to receive any State Pension at all. A qualifying year is one where you earned at least GBP 6,396 (the lower earnings limit) or received NI credits. You don't need 35 consecutive years. Career breaks, periods of unemployment (where you claim benefits), and time spent caring for children under 12 can all count through NI credits. Employees can check their NI record and State Pension forecast through the gov.uk website. HR teams should encourage employees to do this, especially those with gaps in their working history.
NI credits and filling gaps
NI credits protect your pension record when you're not working or earning below the threshold. They're automatically awarded for: receiving child benefit for a child under 12, receiving Jobseeker's Allowance or Employment Support Allowance, receiving Carer's Allowance, and jury service. If you have gaps that aren't covered by credits, you can make voluntary Class 3 contributions (GBP 17.45 per week in 2024/25) to fill them. You can fill gaps going back up to 6 years, and currently (until April 2025) there's an extended deadline to fill gaps back to 2006. Each additional qualifying year adds roughly GBP 329 per year to your State Pension, making voluntary contributions one of the best investments available.
Employer NIC Obligations and Compliance
Employers have significant responsibilities around NIC collection, reporting, and payment.
PAYE real-time information (RTI)
All UK employers must report NICs through HMRC's PAYE RTI system. Every time an employee is paid, the employer submits a Full Payment Submission (FPS) to HMRC showing gross pay, tax deducted, and employee and employer NICs. This must be submitted on or before the pay date. Late submissions trigger penalties. Employer NICs must be paid to HMRC monthly (by the 22nd of the following month for electronic payments, 19th for cheque) or quarterly for small employers. Getting RTI wrong is one of the most common HMRC compliance failures for small businesses.
Employment Allowance
The Employment Allowance reduces employer NICs by up to GBP 5,000 per year. It's available to most businesses with employer NICs below GBP 100,000 in the previous tax year. The allowance is claimed through payroll software and applied against the monthly employer NIC bill. Companies with a single employee who is also a director don't qualify. This is a significant benefit for small businesses. A company with 10 employees earning GBP 25,000 each would save GBP 5,000 per year, effectively making one employee 'NIC-free.' After the April 2025 NIC increase, this allowance becomes even more valuable.
Reduced rates for certain employees
Several NIC reliefs apply to specific employee categories. Under-21s: employer NICs only apply above the upper secondary threshold (GBP 50,270), not the standard secondary threshold. Apprentices under 25: same relief as under-21s. Ex-armed forces veterans in their first year of civilian employment: zero employer NICs on earnings up to the veteran upper secondary threshold. Free port and investment zone employees: zero employer NICs on earnings up to GBP 25,000 for new hires in qualifying areas. These reliefs are designed to incentivize hiring in targeted demographics and regions.
Salary Sacrifice and NIC Savings
Salary sacrifice is the most effective legal method for reducing both employee and employer NICs. It works by exchanging gross salary for non-cash benefits.
How salary sacrifice reduces NICs
When an employee agrees to a salary sacrifice, their contractual salary is reduced. NICs are calculated on the lower salary. The sacrificed amount goes toward a benefit that's either exempt from NICs or taxed at a lower rate. For example, an employee earning GBP 40,000 who sacrifices GBP 5,000 into their pension pays NICs on GBP 35,000 instead of GBP 40,000. The employee saves 8% x GBP 5,000 = GBP 400 in NICs. The employer saves 13.8% x GBP 5,000 = GBP 690 in employer NICs. Combined annual saving: GBP 1,090. Multiply this across hundreds of employees and the numbers become very significant.
Benefits eligible for salary sacrifice
Since April 2017, the range of benefits eligible for salary sacrifice has been restricted. Currently, the following still qualify for full NIC (and tax) savings: employer pension contributions (the most common use case), childcare vouchers (closed to new applicants but existing schemes continue), cycle-to-work schemes, ultra-low emission vehicles (electric and hybrid cars under 75g/km CO2). Other benefits (gym memberships, mobile phones, etc.) are no longer tax-efficient through salary sacrifice because the employee is taxed on the higher of the salary given up or the benefit value.
Risks and considerations
Salary sacrifice reduces gross pay, which affects other calculations: statutory maternity/paternity pay, mortgage affordability assessments, student loan repayments, and State Pension accrual (if salary falls below the lower earnings limit). Employees earning near the national minimum wage can't sacrifice salary below that floor. Employers must ensure that salary sacrifice is a genuine contractual change, not just a payroll adjustment. HMRC has challenged arrangements that don't alter the employment contract.
April 2025 NIC Changes
The October 2024 Autumn Budget announced significant changes to employer NICs that take effect from April 2025.
Rate increase and threshold reduction
Employer NIC rate increases from 13.8% to 15%. The secondary threshold (where employer NICs start) drops from GBP 9,100 to GBP 5,000. Combined, these changes increase the employer NIC cost per employee by approximately GBP 900 for someone earning GBP 30,000 and by approximately GBP 1,250 for someone earning GBP 50,000. The Employment Allowance increases from GBP 5,000 to GBP 10,500 to partially offset the impact for small businesses.
Impact on hiring and compensation decisions
The NIC increase effectively raises the cost of employment by 1.2 to 2 percentage points depending on salary level. Companies are responding in several ways: absorbing the cost (reducing margins), passing costs to consumers through price increases, adjusting salary budgets downward for new hires, accelerating automation investments, and increasing the use of salary sacrifice to offset the additional NIC burden. For HR teams, the key action is modeling the impact on total employment costs and adjusting budgets and headcount plans accordingly.
NI for International and Mobile Employees
Employees working across borders create NI complications. The general principle is that NICs are paid in the country where the work is performed, but several exceptions apply.
EU/EEA and Switzerland: social security coordination
Despite Brexit, the UK has bilateral social security agreements with most EU/EEA countries and Switzerland. Under these agreements, employees posted to the UK for up to 24 months can continue paying social security in their home country and avoid UK NICs (via an A1/E101 certificate). Similarly, UK employees posted abroad can remain in the UK NIC system. Without these agreements, employees could face double contributions. HR teams managing cross-border employees should work with social security advisors to obtain the correct certificates before assignments begin.
Non-EU countries
The UK has bilateral social security agreements with about 20 non-EU countries (including the US, Canada, Japan, South Korea, and India). These agreements prevent double contributions and protect pension rights. For countries without agreements, employees may need to pay social security contributions in both countries. The cost and complexity of international NI compliance is one reason many companies use employer-of-record (EOR) services for overseas hires rather than establishing their own entities.
Frequently Asked Questions
Do I pay National Insurance on bonuses and commissions?
What happens to my NI contributions if I leave the UK?
Is there a difference between NI and income tax?
Do directors pay NI differently?
Can I get a refund of overpaid NI contributions?
Written by Adithyan RK