Voluntary national insurance contributions: how do they work, and how much do they cost? 

It may seem odd to voluntarily pay a tax when you don’t need to, but there are benefits to paying national insurance contributions. 

We explore how NI contributions work, the different classes, the benefits of paying voluntary contributions, and the cost. 

What is national insurance, and how does it work? 

National insurance is a tax on earnings or profits if you’re self-employed. Only those who are over the age of 16 and earn over a specific amount pay NI; we’ll explore this in more detail in the next section.   

Paying NI contributions can help you qualify for benefits such as the state pension, maternity allowance, and jobseeker’s allowance. 

It’s vital you have an NI number and provide it to your employer, so any taxes and contributions are on your record. It’s also a good idea to check your NI record to ensure there are no missing gaps.  

This is because you need at least: 

• 10 qualifying years of NI contributions to get any state pension. 
• 35 qualifying years to get the full state pension (£221.20 a week in 2024/25 tax year and £230.25 in 2025/26).

What happens if you don’t qualify for NI contributions? 

If you don’t qualify for NI contributions, you may be able to get NI credits or make voluntary contributions. 

You may be eligible for NI credits if: 

• You’re looking for employment 
• On maternity, paternity, or adoption pay 
• A carer 
• You cannot work due to a disability or illness 
• You are or have been looking after a child under the age of 12 

Other scenarios in which you can qualify for NI credits are detailed in full on the GOV.UK site.  

When do you pay national insurance? 

You must pay NI if you’re at least 16 years old and either: 

• Earn more than £242 per week from one job 
• Are self-employed with profits of over £12,570 a year 

If you’re not earning enough or your profits don’t meet the threshold, you usually don’t have to pay any NI. Here, your NI contributions are treated as paid to protect your record.  

So, you may still qualify for the state pension and certain benefits if you either: 

• Earn between £123 and £242 a week from one job 
• Are self-employed and your profits are £6,725 or more annually 

It’s worth checking to see if you still qualify for certain benefits if the above applies.  

What are the different classes of national insurance? 

There are many types of NI classes, which apply to different scenarios and have different rates. 

Class 1 

Class 1 NI is automatically deducted from your salary if you’re over 16 but under state pension age and earn over £242 per week from one job. 

You pay 8% if you earn between £242 and £967 a week and 2% if you earn over £967 a week. In some scenarios, you may pay less. 

Employers pay Class 1A and 1B NI contributions.  

If you earn less than £123 per week from one job, you can make voluntary Class 3 NI contributions.  

You stop paying Class 1 NI when you reach state pension age.  

Class 2 

If you’re self-employed, you don’t have to pay Class 2 NI if your trading profits are: 

• Over £12,570 
• Between £6,725 and £12,569 (here, you’re seen as making contributions to protect your record) 

If your trading profits are under £6,725, you can make voluntary contributions, which cost £3.45 a week. 

Class 3 

These are voluntary NI contributions that could boost your entitlement to the state pension and other benefits. Class 3 contributions cost £17.45 a week.  

Class 4 

You may have to pay Class 4 NI if you’re self-employed and have profits of over £12,570 a year. 

You pay: 

• 6% on profits between £12,570 and £50,270 
• 2% on profits over £50,270 

If you’re employed and self-employed, you may have to pay Class 1 and Class 4 contributions.  

If you’re self-employed, you’ll no longer pay Class 4 contributions from the start of the tax year after you reach state pension age.  

Why would someone choose to pay national insurance, and how much does it cost? 

One of the biggest benefits of paying national insurance is eligibility for the state pension. 

This can be tricky, as you need at least 10 years to get anything and 35 years to be eligible for the full amount. 

If you have between 10 and 35 years of qualifying NI years, you’ll get a smaller amount. However, you could use the state pension forecast tool to find out how much you could get. 

While you may well have your own private pensions, these may not be as big as you had hoped, meaning the state pension accounts for a significant proportion of your overall retirement income.

You can pay £17.45 a week for voluntary Class 3 contributions or £3.45 a week if you’re self-employed with trading profits of under £6,725. 

It’s worth checking your NI record and flagging any missing qualifying years or filling any gaps if you can afford it. 

You can currently fill in missing gaps from 2006 to 2016 until 5 April 2025 – after this date, you can only fill in gaps from the last six years. 

When you get a state pension forecast, it will tell you whether you can top up your state pension and how to buy voluntary national insurance contributions. 

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