National Insurance number

GOV.UK says your National Insurance number makes sure your National Insurance contributions and tax are recorded against your name only. It has the format of 2 letters, 6 numbers and a final letter, for example QQ123456B, and it stays the same for life. Your employer needs it to set up payroll, and it links your contributions to things like the State Pension. NHS employers will also ask for it during onboarding.

Check before you apply. GOV.UK says that if you have a BRP or eVisa, you might have a National Insurance number already. You can find it:

• on the back of your BRP
• by signing in to your UKVI account and viewing your eVisa
• later on, on payslips and tax documents such as a P60

If you already have a number, GOV.UK says you do not need a new one, even if your personal details change.

GOV.UK says you can apply if you live in the UK, have the right to work here and are working, looking for work or have a job offer. You can only apply when you are in the UK.

1. Gather an identity document, such as a passport from any country.
2. Apply online on GOV.UK. You will need to prove your identity as part of the application.
3. Read the confirmation email. It gives your application reference and tells you whether you need to provide more proof of identity.
4. If asked, attend an appointment or post photocopies of your documents.
5. Wait for the number. GOV.UK says it can take up to 4 weeks after you have proved your identity.

Yes. GOV.UK says you can start work before you receive your National Insurance number if you can prove you have the right to work. In practice that means your share code for the right to work check. Tell payroll as soon as the number arrives so your tax and contributions are recorded correctly.

GOV.UK lists your employer among the organisations that may need your number. If you cannot remember it, GOV.UK says to check tax documents such as your payslip or P60, where it is usually printed. You can also use the online service to find your National Insurance number, or ask for a letter that confirms it. Keep a note of it with your NHS pension details, because pension forms ask for it too.

• Applying twice. Check your BRP or eVisa first.
• Applying from abroad. You must be in the UK.
• Waiting to start work. You do not need the number on day one.
• Typos on payroll forms. A wrong number can misdirect your contributions; check it against your eVisa or letter.

Our first weeks checklist lists this with bank accounts and GP registration, and the NHS take-home pay calculator shows how National Insurance affects your pay.