Introduction
After looking at a typical payslip, many people notice something surprising.
There are often two deductions based on their earnings:
- Income Tax
- National Insurance
At first glance, they can seem almost identical.
Both are deducted from wages.
Both are collected by the government.
Both help fund the public sector.
So why do they both exist?
Why isn’t there just one tax on earnings?
The answer lies in history.
Although National Insurance is collected alongside Income Tax today, it was created for a different purpose and has followed a different path over the past century.
Understanding National Insurance helps explain not only why two deductions appear on millions of payslips, but also how the UK supports people during retirement, illness and other periods when they may be unable to work.
In the previous chapter, we explored Income Tax, one of the government’s largest sources of revenue. We saw how Income Tax raises money for public services through a progressive system based on earnings.
This chapter explores National Insurance.
It explains what National Insurance is, why it was introduced, how it works today and how it differs from Income Tax. It also examines one of the most common questions people ask:
If National Insurance is collected alongside Income Tax, why does it still exist as a separate system?
By the end of this chapter, you should understand why National Insurance remains an important part of the UK’s public finances and why it continues to play a unique role within the welfare system.
The One Big Idea
National Insurance began as a system of social insurance.
People contributed while they were working so that they could receive financial support if they later became unemployed, too ill to work or reached retirement.
Although the system has changed significantly over time, National Insurance still performs two important functions today.
It raises money that helps fund public spending, and it helps determine eligibility for certain state benefits, particularly the State Pension.
Understanding this historical purpose explains why National Insurance continues to exist alongside Income Tax, even though both are usually collected from earnings.
What Is National Insurance?
National Insurance is a compulsory contribution that many people pay on their earnings.
For most employees, it is deducted automatically from their wages before they receive their salary, alongside Income Tax.
Self-employed people also pay National Insurance, although the rules are different from those that apply to employees.
Unlike Income Tax, National Insurance was not originally designed simply to raise money for the government.
Instead, it was created as part of a system of social insurance.
The basic idea was straightforward.
While people were working, they would make regular contributions.
If they later became unemployed, too ill to work or reached retirement, they could receive support because they had contributed to the system during their working lives.
Although the way National Insurance operates has changed considerably over the years, this idea of making contributions during working life remains an important part of how the system is understood today.
Why Was National Insurance Introduced?
To understand National Insurance properly, it helps to look briefly at its origins.
Before the twentieth century, there was very little organised financial support for people who lost their jobs, became seriously ill or reached old age without sufficient savings.
Many families relied on relatives, charities or local communities for help during difficult times.
As industrialisation transformed Britain, increasing numbers of people depended entirely on wages from paid employment.
If they became unemployed or unable to work, they could quickly lose their income.
This created growing pressure for a more reliable system of financial support.
In the early twentieth century, the government introduced National Insurance as a form of social insurance.
The principle was similar to other forms of insurance.
People would make regular contributions while they were working.
In return, they would become eligible for financial support if certain events occurred, such as illness, unemployment or retirement.
The system expanded significantly after the Second World War, becoming one of the foundations of the modern welfare state.
Over time, healthcare, pensions and social security developed into the systems we recognise today, while National Insurance continued to evolve alongside them.
Although the details have changed over the decades, the original idea remains easy to understand:
people contribute while they are working to help provide financial protection throughout their lives.
How National Insurance Works Today
Today’s National Insurance system is more complex than the one originally introduced over a century ago, but the basic principle remains familiar.
People who earn above certain thresholds generally pay National Insurance contributions during their working lives.
Exactly how much they pay depends on factors such as:
- whether they are employed or self-employed;
- how much they earn; and
- the rules that apply during that tax year.
As with Income Tax, the government reviews these rules regularly through the Budget, so the details may change over time.
Rather than focusing on specific thresholds, it is more useful to understand the overall system.
For most employees, National Insurance is deducted automatically through Pay As You Earn (PAYE) at the same time as Income Tax.
This means that many people pay National Insurance without having to complete any forms or make separate payments themselves.
Although Income Tax and National Insurance often appear together on a payslip, they remain separate systems with different histories, different rules and, in some respects, different purposes.
The next section explores those differences and explains what National Insurance helps to fund today.
What Does National Insurance Pay For?
One of the most common questions people ask is:
“Where does my National Insurance money actually go?”
The answer is slightly more complicated than many people expect.
When National Insurance was first introduced, it operated much more like a traditional insurance scheme.
People made contributions while they were working, and those contributions helped provide financial support if they later became unemployed, became too ill to work or reached retirement.
Today, the system has evolved.
National Insurance contributions are paid into the National Insurance Fund, which helps finance certain areas of government spending, most notably the State Pension and some other contributory benefits. However, the government can also make adjustments between the Fund and general government finances, meaning the system does not operate like a private savings account where each person’s contributions are set aside solely for their own future use.
This is an important point.
When you pay National Insurance, the money is not placed into a personal account with your name on it.
Instead, today’s workers help fund payments being made today, while building up entitlement to certain benefits in the future.
This reflects the principle that has underpinned National Insurance since it began: each generation contributes towards supporting society while helping to maintain the system for future generations.
National Insurance and the State Pension
For most people, the most significant link between National Insurance and future benefits is the State Pension.
Throughout their working lives, people build up a National Insurance record.
This record shows the years in which they have paid, or been credited with, National Insurance contributions.
When someone reaches State Pension age, the number of qualifying years on their National Insurance record helps determine whether they receive the full State Pension or a reduced amount.
This is one of the biggest differences between National Insurance and Income Tax.
Income Tax simply raises revenue for general government spending.
National Insurance, however, continues to play an important role in determining eligibility for certain benefits.
For this reason, keeping an accurate National Insurance record is important, even during periods when someone may not be working.
In some circumstances, people can receive National Insurance credits, for example while caring for children or receiving certain benefits, helping to protect their future State Pension entitlement.
The detailed rules change from time to time, but the underlying principle remains the same:
National Insurance contributions—and credits—help build a record that affects entitlement to the State Pension and certain other benefits.
National Insurance and Other Benefits
Although the State Pension is the best-known example, National Insurance is also linked to some other benefits.
Historically, National Insurance was designed to provide support during several different stages of life, including periods of:
- illness;
- unemployment;
- maternity;
- bereavement; and
- retirement.
Today, some benefits still depend, at least partly, on a person’s National Insurance contribution record.
For example, eligibility for certain contribution-based benefits may depend on whether someone has paid enough National Insurance contributions during previous years.
However, many other benefits are now means-tested, meaning entitlement depends primarily on a person’s income and financial circumstances rather than their National Insurance record.
This means the modern welfare system combines two different approaches.
Some support is linked to National Insurance contributions.
Other support is based on financial need, regardless of previous contributions.
Understanding this distinction helps explain why National Insurance still has a separate identity within the UK’s welfare system.
National Insurance vs Income Tax
Because Income Tax and National Insurance are often deducted from wages at the same time, many people assume they are simply two versions of the same tax.
In reality, there are important differences.
Income Tax is a general tax on income.
The money raised helps fund all areas of government spending, from healthcare and education to defence, transport and environmental protection.
National Insurance has a different history.
It began as a system of social insurance, with contributions helping to fund financial support during retirement, illness and unemployment.
Although today’s system has evolved considerably, National Insurance still retains an important connection with contributory benefits and the State Pension.
Another difference is that the rules governing Income Tax and National Insurance are not always identical.
They may have different thresholds, different rates and different rules depending on whether someone is employed, self-employed or receiving other forms of income.
This is why your payslip usually shows two separate deductions rather than combining them into one.
Although they are collected together, they remain legally distinct parts of the UK’s tax system.
Why Do Employers Pay National Insurance?
Many employees are surprised to learn that they are not the only people paying National Insurance.
Employers also make National Insurance contributions for many members of staff.
Unlike the National Insurance deducted from an employee’s wages, employer National Insurance is paid by the employer in addition to the employee’s salary.
It does not appear as a deduction from the employee’s take-home pay because it is an additional cost paid directly by the employer.
From a business perspective, employer National Insurance is one of the costs of employing staff, alongside wages, pension contributions, training and other employment expenses.
For governments, employer National Insurance provides another important source of public revenue.
For employees, however, it can sometimes be overlooked because they never see it deducted from their own salary.
Understanding employer National Insurance helps explain why the total cost of employing someone is usually higher than their salary alone.
It also illustrates an important economic principle that we first encountered in How Taxes Work:
The person or organisation that pays a tax to the government is not always the only one affected by it. Taxes can influence wages, employment costs, business decisions and investment throughout the wider economy.
Why Has National Insurance Changed Over Time?
National Insurance has now existed for well over a century.
During that time, British society has changed enormously.
People are living longer.
Healthcare has advanced.
Patterns of employment have changed.
The welfare system has evolved.
As a result, National Insurance has changed too.
When it was first introduced, National Insurance was designed much more like a traditional insurance scheme.
Workers made contributions and, in return, became entitled to support during periods of unemployment, sickness or retirement.
Over the decades, however, successive governments have introduced new benefits, reformed existing ones and changed the relationship between National Insurance and general taxation.
Today, National Insurance still plays an important role, but it no longer operates as a simple insurance policy in the way many people imagine.
Instead, it forms part of a much broader system of public finance and social security.
The principles of contribution and entitlement remain important, particularly for the State Pension and some contributory benefits, but the system has adapted to reflect the needs of a modern economy and an ageing population.
Like many public institutions, National Insurance has evolved rather than remaining fixed.
Understanding that evolution helps explain why some features of the system seem historical while others feel similar to general taxation.
Why Does National Insurance Still Exist?
Given that Income Tax and National Insurance are both collected from earnings, people sometimes ask why they have not simply been merged into a single tax.
There is no single answer, but there are several reasons why National Insurance continues to exist as a separate system.
Its Historical Role
National Insurance has a long history as part of the UK’s welfare system.
For many people, the idea of contributing towards future benefits remains an important principle, even though the system has changed considerably over time.
Keeping National Insurance separate helps preserve that historical connection.
The Contributory Principle
One of the defining features of National Insurance is the contributory principle.
The basic idea is that paying, or receiving credits for, National Insurance contributions helps build entitlement to certain state benefits.
Supporters argue that this creates a clearer link between contributions made during working life and some of the benefits received later.
Although the modern welfare system also includes many means-tested benefits, the contributory principle remains an important part of National Insurance.
Different Policy Choices
Keeping National Insurance separate also gives governments greater flexibility.
Governments can change National Insurance rates, thresholds or rules independently from Income Tax if they wish.
This allows different policy decisions to be made without necessarily changing the entire Income Tax system.
Whether this flexibility is an advantage is a matter of political debate, but it helps explain why the two systems continue to exist separately.
Why Do Some People Want Reform?
National Insurance has existed for many decades, but it continues to generate discussion about whether the system should be modernised.
Some people argue that the current system is unnecessarily complicated.
Because both Income Tax and National Insurance are usually based on earnings and collected through PAYE, they believe the two systems should be merged into a single, simpler tax.
Supporters of this approach argue that it would make payslips easier to understand, reduce administrative complexity and create a more transparent tax system.
Others take a different view.
They argue that National Insurance should remain separate because it preserves the contributory principle and maintains the historical link between contributions and certain state benefits, particularly the State Pension.
Some also believe that keeping National Insurance separate helps people understand that contributions made during working life support important parts of the welfare system.
There are therefore reasonable arguments on both sides.
As with many questions in public finance, there is no single solution that everyone agrees upon.
The purpose of this chapter is not to recommend one approach over another, but to explain why the debate exists and how the current system works.
Why National Insurance Matters
For millions of people, National Insurance is simply another deduction on a payslip.
Yet it plays a much broader role within the UK’s system of public finance and social security.
It raises billions of pounds each year.
It helps fund important areas of government spending.
It contributes towards the financing of the State Pension and some other contributory benefits.
It also provides the National Insurance record that helps determine entitlement to certain future benefits.
Understanding National Insurance therefore has practical value.
It helps people understand:
- why two deductions appear on their payslip;
- why employers also make National Insurance contributions;
- how entitlement to the State Pension is built up; and
- why National Insurance remains separate from Income Tax.
More broadly, National Insurance demonstrates how public policy evolves over time.
Institutions created to solve one problem often continue to develop as society changes.
Rather than remaining exactly as they were when first introduced, they adapt to new economic conditions, demographic changes and political priorities.
National Insurance is a good example of this gradual evolution.
Understanding that evolution helps explain not only how the system works today, but also why debates about its future continue.
National Insurance Within the Wider Tax System
This chapter has focused on one particular deduction from earnings.
However, National Insurance is only one part of the UK’s overall tax system.
In the previous chapter, we explored Income Tax, which raises revenue from personal earnings.
The next chapter examines a very different kind of tax.
Instead of taxing income, it taxes spending.
That tax is Value Added Tax (VAT).
By understanding both Income Tax and National Insurance, you now have a much clearer picture of how earnings are taxed in the UK.
The next step is to explore what happens when we spend the money we have earned.
Common Misunderstandings
National Insurance has existed for more than a century, yet many people are unsure exactly how it works.
Because it often appears alongside Income Tax on a payslip, it is easy to assume that the two systems are identical.
In reality, National Insurance has its own history, its own rules and its own purpose.
Let’s look at some of the most common misunderstandings.
“National Insurance Is the Same as Income Tax”
This is probably the most common misconception.
Both deductions are usually taken from wages through PAYE, which makes them appear very similar.
However, they are different systems.
Income Tax is a general tax that helps fund all areas of government spending.
National Insurance began as a system of social insurance and still helps determine entitlement to certain state benefits, particularly the State Pension.
Although both contribute to the UK’s public finances, they have different histories and are governed by different rules.
“My National Insurance Contributions Are Saved in My Own Account”
Some people imagine that their National Insurance contributions are paid into a personal account that they will later receive back during retirement.
That is not how the system works.
National Insurance is not a personal savings account.
Instead, today’s contributions help support today’s public finances and contributory benefits, while also building a National Insurance record that may affect entitlement to certain future benefits.
This means your contributions help support the system as a whole rather than being reserved exclusively for your own future use.
“Only Employees Pay National Insurance”
Employees are not the only people who pay National Insurance.
Many self-employed people also make National Insurance contributions, although the rules differ.
In addition, employers often pay National Insurance contributions for their employees.
This means that National Insurance is shared across employees, employers and many self-employed workers.
“Paying National Insurance Guarantees Every State Benefit”
Paying National Insurance is important, but it does not automatically entitle someone to every government benefit.
Some benefits are contributory, meaning that entitlement depends partly on a person’s National Insurance record.
Others are means-tested, meaning they depend mainly on a person’s income and financial circumstances.
Understanding this distinction helps explain why the modern welfare system combines different forms of support rather than relying solely on National Insurance contributions.
“National Insurance Only Pays for the State Pension”
The State Pension is one of the best-known parts of the National Insurance system, but it is not the only one.
National Insurance has historically supported a wider range of contributory benefits, and today the money raised forms part of the wider financing of public spending as well as supporting the National Insurance Fund.
This is why it is more accurate to think of National Insurance as part of the UK’s overall system of taxation and social security rather than simply a pension contribution.
Conclusion
National Insurance is one of the oldest parts of the UK’s system of public finance.
Although it began as a form of social insurance, it has evolved alongside changes in society, the economy and the welfare state.
Today, National Insurance performs two important roles.
It raises revenue that helps support public spending, while also helping to determine entitlement to certain contributory benefits, particularly the State Pension.
Understanding National Insurance also helps explain why two deductions appear on many payslips.
Although Income Tax and National Insurance are often collected together, they are not the same.
They have different histories, different purposes and, in some cases, different rules.
Together, they form two of the most important sources of revenue linked to earnings.
More broadly, National Insurance illustrates an important theme that runs throughout Fair Society.
Public institutions often evolve over many decades.
Rather than remaining exactly as they were when first created, they adapt to changing economic conditions, demographic trends and the needs of society.
National Insurance is a good example of this gradual evolution.
Understanding how it has changed over time helps us understand not only today’s tax system, but also how public policy itself develops.
Continue Learning
You now understand why National Insurance exists and how it differs from Income Tax.
You have learned:
- why National Insurance was introduced;
- how it has evolved over time;
- who pays National Insurance;
- what it helps fund;
- how it contributes to eligibility for the State Pension and certain other benefits; and
- why it remains separate from Income Tax.
So far, we have explored the two main deductions that most employees see on their payslips.
The next chapter examines a different kind of tax altogether.
Instead of taxing earnings, Value Added Tax (VAT) is charged when people spend money on many goods and services.
Understanding VAT completes another important part of the UK’s tax system and shows how governments raise revenue not only from income, but also from consumption.
Together, Income Tax, National Insurance and VAT explain how most people contribute to government revenue throughout their everyday lives—whether they are earning, working or spending.