Do I need a National Insurance number to start work?

No. You do not need an NI number before you start work. Your employer can pay you without one. However, you may be taxed at an emergency rate until your NI number is allocated. Once you have it, your tax code will be corrected and any overpaid tax will be refunded.

How do I apply for a National Insurance number?

You apply by calling the National Insurance number application line on 0800 141 2075. They will ask for your personal details and may send you an application form or invite you to an interview at a Jobcentre Plus. Some people receive their NI number automatically when their visa is granted. Check your eVisa or decision letter.

How long does it take to get a National Insurance number?

Processing times vary but typically take 4 to 8 weeks from application. During busy periods, it can take longer. You will receive your NI number by post in a letter. Do not call to chase the application unless it has been more than 16 weeks.

Is my National Insurance number linked to my visa?

Your NI number is permanent and does not expire, even if your visa expires. However, having an NI number does not prove your right to work. Employers must check your immigration status separately through the share code system or your eVisa. An NI number is a tax reference, not an immigration document.

Getting a National Insurance Number in the UK

Q: What is a National Insurance number?

A National Insurance (NI) number is a unique reference number used in the UK tax and benefits system. It is formatted as two letters, six numbers, and one letter (e.g., AB 12 34 56 C). You need it to work legally in the UK, pay the correct amount of tax, and access certain government services.

Your National Insurance (NI) number is a unique reference for the UK tax system. You need one to work and pay tax, but you do not need it before you start your job. Some visa holders receive one automatically; others need to apply by phone. This guide covers the full process.

What Is a National Insurance Number?

A National Insurance (NI) number is your personal reference number for the UK tax and benefits system. It is used by:

HM Revenue and Customs (HMRC) to track your tax and National Insurance contributions
Your employer to process your pay and deductions
The Department for Work and Pensions (DWP) for benefits and state pension
Local councils for council tax purposes

The format is two letters, six numbers, and a final letter (for example, AB 12 34 56 C). Once allocated, your NI number stays with you for life. It does not change if you change jobs, addresses, or visa status.

Do You Already Have One?

Some visa holders are allocated an NI number automatically as part of the visa decision process. Check:

Your visa decision letter or email
Your eVisa online status page
Any correspondence from the Home Office

If you can see an NI number in any of these places, you do not need to apply separately. Make a note of it and give it to your employer.

If you do not have one, you need to apply. The process is straightforward but can take several weeks.

How to Apply

Call the NI number application line: 0800 141 2075 (Monday to Friday, 8am to 5pm). The call is free.
Provide your details. The operator will ask for your name, date of birth, address, nationality, visa type, and reason for applying (usually "I need an NI number to work").
You may be sent a form. In some cases, you will be sent a CA5403 form to complete and return by post.
You may be invited to a Jobcentre Plus interview. This is more common for some nationalities. The interview is informal and used to verify your identity.
Wait for your NI number. It arrives by post, typically within 4 to 8 weeks.

You can also write to the National Insurance Contributions Office, but calling is faster and is the recommended method.

Working Without an NI Number

This is an important point: you do not need an NI number to start working. Your employer can employ you and pay you without one. What typically happens is:

Your employer assigns you an emergency tax code
You may pay more tax than usual under the emergency code
Once your NI number is allocated and registered with HMRC, your tax code is corrected
Any tax you overpaid is refunded through your salary or your annual tax return

No employer should refuse to hire you or delay your start date solely because you do not yet have an NI number. If they do, direct them to the HMRC guidance which confirms this.

NI Number vs Right to Work

It is important to understand that an NI number is not proof of your right to work. They are separate things:

Right to work: Proved through your eVisa share code or other immigration documents. Your employer checks this before you start work.
NI number: A tax reference used by HMRC. It does not confirm your immigration status or your permission to work.

An NI number remains active even after your visa expires. This does not mean you can continue working. Your right to work ends when your visa ends (unless you have Section 3C leave or ILR).

National Insurance Contributions

Once you start working, you will pay National Insurance contributions (NICs) through your salary. These contributions:

Fund the state pension and certain benefits
Are deducted automatically from your pay by your employer
Build up your entitlement to the state pension over time

In 2026, employees pay 8% on earnings between £12,570 and £50,270 per year, and 2% on earnings above £50,270. Your employer also pays NICs on your behalf.

Your NI contribution record matters if you eventually apply for British citizenship or claim the state pension. It is worth checking your record periodically through your personal tax account on GOV.UK.

Common Issues

I lost my NI number

Check old payslips, P60 forms, or letters from HMRC. You can also find it in your personal tax account on GOV.UK. If you still cannot find it, call the NI helpline on 0300 200 3500.

My NI number application is taking too long

Processing can take up to 16 weeks during busy periods. If it has been more than 16 weeks, call the application line to check the status.

My employer is insisting I need an NI number before I start

This is incorrect. Show them the HMRC guidance. You have the legal right to start work as long as you have the right to work in the UK (proved through your visa or eVisa).

Next Steps

Check whether you already have an NI number from your visa decision. If not, call the application line as soon as possible after arriving in the UK. Do not delay starting work while you wait.

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