What is National Insurance?
By Tom Wilson
What is National Insurance?
Find out everything you need to know about National Insurance and your National Insurance number.
In this two-minute video, Which? gives a brief overview of how National Insurance works.
In this guide, explain how National Insurance works, who has to pay into the system and how to find your National Insurance number.
Use the links below to find out:
- What is National Insurance?
- Who pays National Insurance?
- Why do I need to pay National Insurance?
- Making National Insurance contributions
- What is my National Insurance number?
- How do I apply for a National Insurance number?
- Help with my National Insurance number
Find out more: Which? Tax calculator - to help you work out how much National Insurance you owe
National Insurance is a tax on earnings and self-employed profits.
Your National Insurance contributions are paid into a fund, from which some state benefits are paid. This includes the state pension, statutory sick pay or maternity leave, or entitlement to additional unemployment benefits.
National Insurance is paid by employers, as well as employees and self-employed workers, until they reach state pension age.
You'll pay National Insurance until you reach state pension age, providing your income (or profits) are above a certain level.
In some cases you may qualify for National Insurance credits, perhaps if you are earning a modest wage, or are acting as a carer.
If you're not currently paying into National Insurance, you can also elect to make voluntary contributions.
Find out more: National Insurance contributions - find out who pays what
Paying National Insurance entitles you to some state benefits, though these vary according to whether you're employed, self-employed or making voluntary contributions.
You'll need to pay into National Insurance for a set number of years to be entitled to receive the state pension.
If you haven't met the minimum amount of contributions, you may not qualify for some benefits.
Find out more: how do I qualify for the state pension? – when you'll qualify, and what you need to do in advance.
If you're employed, National Insurance is automatically deducted from your monthly pay.
If you're self-employed, you'll need to organise these contributions yourself, usually through your self-assessment tax return.
Either way, to ensure you pay the right amount of tax, it's important to check that you have the correct tax code.
Find out more: National Insurance rates – a detailed breakdown of how much you'll have to pay
National Insurance numbers are set by the Department of Work and Pensions.
Each number is unique - they are used to identify you so the government knows how much tax you have paid, how much state pension you might be owed, and to track your tax allowances.
Each person is only assigned one National Insurance number and you'll use the same one throughout your life.
Your National Insurance number contains two letters, six numbers and a final letter.
If you are a UK national, you should receive an NI number (and NI card) automatically before you turn 16.
If you didn’t, and are under 20, call the National Insurance number helpline (0300 200 3500). If you are older than 20, call the National Insurance application line on 0800 141 2075.
This office is only open Monday to Friday. You’ll need ID, and may need to attend an interview.
If you are moving to the UK, you may have a National Insurance number allocated on your biometric residence permit. If not, you must apply once you are in the UK by calling the helpling number on 0800 141 2075.
Below are some commonly asked questions related to your National Insurance card.
Your National Insurance number is fixed for life, so if you lose it, you can’t get a new one.
You may be able to find your National Insurance number by logging into your online tax account, if you have one, or by checking your payslip.
If you can’t find it, call the helpline on 0300 200 3500. You’ll need to answer some questions, and may need to attend an interview to prove your identity.
British residents were previously issued with a National Insurance card, but these were phased out by the end of 2011.
Now, new applicants and people reaching the age of 16 are sent a letter by HMRC listing their National Insurance number.
You therefore no longer need a National Insurance card to apply for jobs - the letter from HMRC should be enough evidence of your NI number.
National Insurance cards were phased out in 2011.
If you lose your card, you will need to contact the helpline on 0300 200 3500 to be issued a letter stating your NI number.
You may be asked to show the letter as proof of your NI number when you start employment.
You need to apply for an NI number before you start work in the UK.
However, you can start working before your National Insurance number arrives if you can prove your right to work in the UK - for example, by showing your visa.
When you receive your NI number, make sure your employer updates their records.
If you accidentally provide the wrong NI number, HMRC may not be able to match your contributions to your records.
Generally, HMRC staff will attempt to match erroneous NI numbers with the right person based on other information provided.
As a first step, check your National Insurance record to see if there are gaps where contributions or credits have not been counted. If so, talk to your employer and ask for your records to be corrected.
Otherwise, contact HMRC on 0300 200 3500 about the error. You may be asked to show proof of your employment, like P60s or payslips.
It's important to keep track of how much you've paid into National Insurance, and whether there are any gaps or credits.
You can check your National Insurance record online via the government portal.
Alternatively, you can request a paper copy of your National Insurance Statement to be mailed to you by writing to:
National Insurance contributions and Employers Office
HM Revenue and Customs
- Last updated: February 2018
- Updated by: Tom Wilson