Getting your National Insurance number

Your National Insurance number is a unique personal reference used by HM Revenue and Customs and the Department for Work and Pensions to track your tax, contributions, and benefits throughout your life in the UK. If you have recently arrived, you may already have one without realising it, or you might need to apply. Here is everything you need to know.

Do you already have one? Check your BRP or eVisa first

Many newcomers assume they need to apply immediately, but you may already have a National Insurance number issued as part of your visa process. The Home Office prints National Insurance numbers on some Biometric Residence Permits, usually on the back in the remarks field, depending on your immigration category and the date your permit was issued. Not all BRPs carry a number, and the Home Office does not publish specific criteria, so always check the reverse of your card carefully.

If you hold an eVisa rather than a physical card, your National Insurance number may appear when you log into your UK Visas and Immigration account online. Some eVisa holders who would have received a number printed on a BRP can see it displayed for their reference on their status profile, though it is not shared via the right to work share code. If it is there, that is your permanent number. You do not apply for another one. Your National Insurance number never changes, even if your name, address, visa status, or any other personal details change later.

Who needs to apply, and when

If you do not already have a National Insurance number and you plan to work, you must apply for one. To be eligible, you need to live in the UK, have the right to work here, and either be working already, have a confirmed job offer, or be actively looking for work. You can only apply once you are physically in the UK. You cannot submit an application from abroad, and you will need a UK address to receive correspondence.

You do not need a National Insurance number to apply for most benefits or for a student loan. If you apply for Universal Credit or another benefit without a number, the Department for Work and Pensions may contact you and help you obtain one as part of your claim. Similarly, student finance applications can proceed without a number, though you may be asked to provide it later.

The application process step by step

Applying for a National Insurance number is done online through the official government service. The process is free. Any website that charges a fee for the application is not an official service and should be avoided.

Before you start

Gather your identity documents. You will need to prove who you are during the application. Acceptable documents include your passport, national identity card, Biometric Residence Permit, or a Home Office travel document. If you do not have any of these, you can still apply, but your application will take longer because you may need to attend an appointment in person or post photocopies of your documents.

Submitting your application

Visit the official application page at gov.uk/apply-national-insurance-number and complete the online form. You will be asked to confirm your eligibility, provide personal details including your UK address, and answer questions about your employment status and right to work. The system may ask you to take digital photos of your identity documents and a photo of yourself holding your passport. You may be allowed to use a smartphone or tablet for this. If you cannot complete the identity check online, you will receive instructions via email about what to do next.

Once you submit your application, you will receive an email confirmation with an application reference number. Keep this email. You will need the reference number if you contact HMRC or the National Insurance number helpline for updates. The email will also tell you if you need to provide further proof of identity.

How long it takes

It can take up to four weeks to receive your National Insurance number after you have proved your identity. The number will be sent to you by post at the address you provided in your application. There is no option to receive it by email or text message. If you move house during this time, you may need to update your address by contacting the helpline using the reference number in your confirmation email.

Working while you wait for your number

You can start work before you receive your National Insurance number. This is explicitly allowed, and your employer cannot refuse to hire you or delay your start date solely because your number has not arrived. What matters for employment purposes is your right to work in the UK, which is proved using your passport, visa, Biometric Residence Permit, or share code from your eVisa account. Your National Insurance number is not proof of your right to work. Employers must check your immigration status separately and are not allowed to rely on a National Insurance number for this purpose.

When you start work without a National Insurance number, tell your employer that you have applied and give them your application reference number or a copy of the confirmation email. Your employer will set up your payroll record using your name, date of birth, and address. They will submit your details to HMRC via the Real Time Information system, and HMRC will create a temporary reference for you. This is not a number you will use yourself. It is an internal code used by HMRC to track your tax and National Insurance contributions until your permanent number arrives.

Once your National Insurance number is issued and you receive the letter, give the number to your employer immediately. Your employer will update your payroll record and send the number to HMRC. HMRC will then match your temporary record with your new permanent number, ensuring that all the tax and National Insurance you have already paid is correctly recorded against your name. This matching process is automatic and usually takes a few weeks, though it can occasionally take longer.

Tax codes and deductions

If you start work without a National Insurance number and your employer does not have a P45 form from your previous job, you may initially be placed on an emergency tax code. This can result in higher tax deductions from your first few pay packets. Once HMRC receives your details and assigns you the correct tax code, any overpaid tax should be refunded automatically through your payroll, though in some cases you may need to contact HMRC to claim it back. Keep all your payslips so you have a record of what has been deducted.

What to do once your number arrives

When your National Insurance number arrives by post, keep the letter in a safe place. The letter is your official confirmation and it is useful to have it to hand when dealing with HMRC, the Department for Work and Pensions, your employer, pension providers, or your bank if you open an Individual Savings Account. If you lose the letter, your National Insurance number will also appear on your payslips, your P60 end of year certificate, and any correspondence from HMRC or the DWP. You can also view it by logging into your Personal Tax Account on GOV.UK or using the HMRC app.

Your National Insurance number is personal and should be kept secure. Although it is not as sensitive as your bank details or passwords, it can be used by fraudsters to impersonate you when dealing with HMRC or benefit offices. Only give your number to people or organisations that genuinely need it, such as your employer, HMRC, the Department for Work and Pensions, pension providers, or your bank for certain accounts. Be cautious of anyone contacting you unexpectedly and asking for your number. HMRC will never call you from a mobile number, email you a link asking for personal details, or threaten you with immediate legal action.

If you need help or have questions

If you have questions about your application or need to check its status, you can contact the National Insurance number application helpline. For England, Scotland, and Wales, call 0800 141 2079, Monday to Friday, 8am to 5pm. For Northern Ireland, call 0800 587 0024, Monday to Friday, 9am to 4pm. Have your application reference number ready when you call. If you use Relay UK or need a British Sign Language video relay service, those options are available on the same numbers.

Citizens Advice and the Low Incomes Tax Reform Group also publish free, independent guidance about National Insurance numbers, eligibility, and what to do if you encounter problems with your application or employer. If your employer refuses to let you start work without a number, or tells you that you cannot be paid until it arrives, that is incorrect. You have the right to work and be paid as long as you can prove your right to work in the UK.