What Is National Insurance? UK NI Guide 2025

Everything you need to know about National Insurance contributions, rates, credits, and your State Pension record.

Last updated: February 2026  |  2025/26 tax year data

Author: Mustafa Bilgic (MB)  |  Expertise: UK Taxation & Personal Finance  |  Reading time: ~10 minutes

National Insurance (NI) is one of the most important taxes in the UK, yet many people have only a vague understanding of what it actually is, how much they pay, and what they get in return. This comprehensive guide explains everything you need to know about National Insurance in 2025, from the rates and thresholds to how contributions protect your State Pension entitlement.

What Is National Insurance?

National Insurance is a system of contributions paid by employees, employers, and the self-employed in the United Kingdom. It was introduced in 1948 as part of the post-war welfare state and is administered by HM Revenue and Customs (HMRC). NI contributions go into the National Insurance Fund, which is used to pay for:

Despite being called an "insurance", National Insurance is effectively a tax on earnings. There is no direct link between what you pay in and what you receive — but there is a link between the number of years you contribute and your State Pension entitlement. This makes understanding your NI record genuinely important for your long-term financial security.

Key fact: In 2025/26, the UK government collects approximately £180 billion per year in National Insurance contributions — making it the second-largest source of government revenue after income tax.

NI Rates and Thresholds 2025/26

For the 2025/26 tax year, the National Insurance thresholds and rates for employees (Class 1) are as follows. These thresholds have been frozen until 2028, meaning that as wages rise, more workers are pulled into higher bands — a process known as fiscal drag.

Earnings Band (Annual) Weekly Equivalent NI Rate (Employee)
Up to £12,570 (Lower Profits Limit / Primary Threshold) Up to £242 0%
£12,570 to £50,270 £242 to £967 8%
Above £50,270 (Upper Earnings Limit) Above £967 2%

It is worth noting that the employee NI rate was reduced from 12% to 10% in January 2024, and then further to 8% from April 2024. These cuts represented the largest reduction in NI in over 30 years.

Employer NI Rates 2025/26

Employers also pay National Insurance on their employees' wages. From April 2025, significant changes were made to employer NI:

Threshold 2024/25 2025/26
Secondary Threshold (employer NI kicks in) £9,100/year £5,000/year
Employer NI Rate 13.8% 15%
Employment Allowance £5,000 £10,500

The increase in employer NI from 13.8% to 15%, combined with the reduction in the secondary threshold from £9,100 to £5,000, means employers pay significantly more NI per employee from April 2025. The Employment Allowance — available to smaller businesses — was increased to £10,500 to partially offset this increase.

How NI Affects Your Take-Home Pay

National Insurance is deducted from your gross pay by your employer before you receive it — just like income tax under PAYE. To illustrate the impact on take-home pay, here are some examples for 2025/26:

Annual Salary Taxable NI Annual NI (Employee) Monthly NI Deduction
£20,000 £7,430 £594 £50
£30,000 £17,430 £1,394 £116
£40,000 £27,430 £2,194 £183
£50,270 £37,700 £3,016 £251
£60,000 £37,700 + £9,730 £3,212 £268

Classes of National Insurance

National Insurance is divided into different "classes" depending on your employment status and earnings. Understanding which class applies to you is essential for knowing what you are contributing and what you are entitled to.

Class 1

Paid by employees and employers. Deducted automatically via PAYE. Builds entitlement to State Pension and contributory benefits.

Class 2

Paid by self-employed people with profits of £12,570 or more. A flat rate of £3.45 per week in 2025/26. Builds State Pension entitlement.

Class 3

Voluntary contributions to fill gaps in your NI record. Currently £17.45 per week (2025/26). Does not give entitlement to contributory benefits.

Class 4

Paid by self-employed people on profits above £12,570. Rate is 6% on profits between £12,570 and £50,270, then 2% above £50,270.

Class 1A and Class 1B

There are also two additional employer-only classes:

NI and the State Pension

Your National Insurance record is the primary factor determining your State Pension entitlement. The new State Pension (for those who reached State Pension age on or after 6 April 2016) works as follows:

Qualifying Years State Pension Entitlement Weekly Amount (2025/26)
Fewer than 10 years No State Pension £0
10 years Minimum partial pension ~£63.20
20 years Partial pension ~£126.40
35 years (full) Full new State Pension £221.20

The full new State Pension in 2025/26 is £221.20 per week (£11,502.40 per year), representing a 4.1% increase due to the triple lock guarantee, which increases the State Pension by the highest of: inflation (CPI), earnings growth, or 2.5%.

Each qualifying year adds approximately £6.32 per week to your State Pension (£221.20 ÷ 35 qualifying years). This is a significant return on investment, particularly for voluntary contributions.

State Pension Age

The current State Pension age is 66 for both men and women. It is scheduled to rise to 67 between 2026 and 2028, and then to 68 in the future (though the government continues to review this timeline). You can check your personal State Pension age at gov.uk.

National Insurance Credits

National Insurance credits are a way of adding qualifying years to your NI record when you are not working or earning enough to make contributions. They are crucial for protecting your State Pension entitlement during periods when you cannot pay NI.

Who Can Get NI Credits?

You may automatically receive NI credits if you:

Important tip for parents: If you are a stay-at-home parent or working parent who is not claiming Child Benefit (because your household income exceeds the threshold), you may be missing valuable NI credits. Even if you pay back the Child Benefit via the High Income Child Benefit Tax Charge, claiming it protects your NI record. Parents of children under 12 can also claim Specified Adult Childcare credits if the main carer does not need the credits.

Specified Adult Childcare Credits

A grandparent or other family member who looks after a child under 12 while the parent is working may be able to apply for Specified Adult Childcare credits. These credits are transferred from the parent's NI record (who does not need them, as they are already earning NI credits through work) to the grandparent. This is particularly valuable for grandparents who are not yet at State Pension age.

Gaps in Your NI Record

A gap in your NI record occurs when you have a year in which you did not make sufficient NI contributions and did not receive NI credits. Common reasons for gaps include:

A gap means that year does not count as a qualifying year towards your State Pension. If you already have 35 or more qualifying years, additional gaps make no difference. However, if you have fewer than 35 qualifying years, each gap potentially reduces your State Pension entitlement by approximately £6.32 per week.

Voluntary NI Contributions

If you have gaps in your NI record that are reducing your State Pension entitlement, you can pay voluntary Class 3 contributions to fill them. The cost and potential benefit are as follows for 2025/26:

Item Amount
Class 3 voluntary rate (2025/26) £17.45 per week
Cost to fill one full gap year ~£907
Additional State Pension per week ~£6.32
Additional State Pension per year ~£329
Break-even point (years to recoup cost) ~2.8 years

Given the break-even point of less than three years, paying voluntary contributions is almost always worthwhile if you are short of the 35 qualifying years needed for the full State Pension, provided you live beyond your early 70s. The return on investment is exceptional compared to most savings products.

Deadlines for Filling Gaps

Normally, you can only pay voluntary contributions to fill gaps in the previous six tax years. However, a temporary extension was put in place allowing people to fill gaps going back to 2006/07 — this extended deadline was initially April 2025 and has been subject to further government announcements. Always check gov.uk for the current deadline before making decisions.

Class 2 Voluntary Contributions for the Self-Employed

Self-employed people with low profits (below £6,725) can pay voluntary Class 2 contributions at just £3.45 per week — significantly cheaper than Class 3 contributions. This gives them the same State Pension entitlement as paying Class 3, making it an even better deal for those who qualify.

How to Check Your NI Record

You can check your National Insurance record online through the HMRC Personal Tax Account or the Government Gateway. Here is what you can see:

To access your NI record, go to gov.uk/check-national-insurance-record. You will need a Government Gateway user ID and password. If you do not have one, you can create one during the process — you will need your National Insurance number and some identifying information such as a passport or payslip.

Special Cases and Exemptions

NI and State Pension Age

Once you reach State Pension age (currently 66), you stop paying Class 1 NI contributions, even if you continue working. Your employer continues to pay employer NI on your salary. If you are self-employed and reach State Pension age, you also stop paying Class 2 and Class 4 contributions.

Directors and NI

Company directors are treated as employees for NI purposes but have their NI calculated on an annual basis rather than per pay period. This means that if a director takes a large dividend early in the year and no salary, they may pay a different pattern of NI compared to a salaried employee.

NI and Zero-Hours Contracts

Workers on zero-hours contracts only pay NI when their weekly earnings exceed the Lower Earnings Limit (£123 per week / £6,396 per year in 2025/26). However, you only receive a qualifying year for State Pension purposes if your annual earnings in that employment exceed £6,396. This can create gaps in the NI records of those in insecure employment.

NI for Workers from Abroad

People who come to work in the UK from abroad pay NI in the same way as UK residents from day one of employment. Some countries have reciprocal social security agreements with the UK that may affect your liability — particularly relevant for workers from EU countries, the USA, Canada, and other nations with bilateral agreements.

Impact of NI Changes Over Time

National Insurance has changed substantially in recent years. Here is a summary of recent and upcoming changes:

Date Change Impact
July 2022 Primary threshold raised from £9,880 to £12,570 Saving of up to £330/year for employees
January 2024 Employee main rate cut from 12% to 10% Average worker saved ~£450/year
April 2024 Employee main rate cut further to 8% Additional saving of ~£450/year
April 2025 Employer rate raised 13.8% to 15%; secondary threshold cut to £5,000 Employers pay more; Employment Allowance doubled to £10,500
April 2028 Threshold freeze expected to end Possible real-terms change to tax burden
Disclaimer: This article is for informational purposes only and does not constitute financial or tax advice. NI rates and thresholds are set by the government and may change. Always verify current rates at gov.uk or consult a qualified financial adviser before making decisions about voluntary NI contributions.

Frequently Asked Questions

What is National Insurance and why do I pay it?
National Insurance (NI) is a tax on earnings paid by employees, employers, and the self-employed. It funds State Pension, Jobseeker's Allowance, Maternity Allowance, and the NHS. You build up entitlement to these benefits by accumulating qualifying years on your NI record. In 2025/26, employees pay 8% on earnings between £12,570 and £50,270, and 2% above that.
What are the National Insurance rates for 2025/26?
For 2025/26, employees pay Class 1 NI at 8% on earnings between £12,570 and £50,270 per year, and 2% on earnings above £50,270. Employers pay 15% on earnings above the secondary threshold of £5,000 (increased from 13.8% and with a lower threshold than 2024/25). Self-employed people pay Class 2 at £3.45/week and Class 4 at 6% on profits between £12,570 and £50,270.
How many NI qualifying years do I need for a full State Pension?
You need 35 qualifying years of National Insurance contributions to receive the full new State Pension (£221.20 per week in 2025/26). You need at least 10 qualifying years to receive any State Pension at all. Each qualifying year below 35 reduces your pension by approximately £6.32 per week.
What are NI credits and who can get them?
NI credits are credits added to your NI record when you are not working or earning enough to make NI contributions. You may be eligible if you claim Child Benefit for a child under 12, receive Jobseeker's Allowance, are on sick leave, or are a carer. They protect your State Pension entitlement without requiring you to make actual NI payments.
How do I check my NI record and find any gaps?
You can check your NI record online through the Government Gateway at gov.uk/check-national-insurance-record. You will need a Government Gateway user ID and password. The record shows your qualifying years, any gaps, and your State Pension forecast. The check is free and takes only a few minutes to access.
Can I fill gaps in my National Insurance record?
Yes. You can pay voluntary Class 3 NI contributions to fill gaps in your record, currently £17.45 per week for 2025/26. Filling a gap costs around £907 for a full year and could increase your State Pension by around £6.32 per week (£329 per year), meaning you recoup the cost in under three years. This makes voluntary contributions an excellent investment for most people with gaps.
Do I pay National Insurance after State Pension age?
No. Once you reach State Pension age (currently 66 for both men and women), you stop paying Class 1 National Insurance contributions, even if you continue to work. However, your employer continues to pay employer NI contributions on your wages. If you are self-employed, you also stop paying Class 2 and Class 4 contributions at State Pension age.