National Insurance number for people new to the UK

Who needs one, how long it takes and why it matters for your pay.

The short answer

If you come to the UK to work, you need a National Insurance (NI) number. It is how your tax and National Insurance contributions are recorded, and it counts towards some benefits and the State Pension. You can start work before you receive it if you can prove your right to work. It is free to apply, and it can take up to four weeks.

Who needs one

You need one if you live in the UK, have the right to work here, and plan to work.
You may already have one. Some people with a biometric residence permit or an eVisa already have a number, which you can check through your UK Visas and Immigration account.
Apply through GOV.UK. Be wary of anyone offering to apply for you for a fee.

Why it matters for your money

Your employer uses it so that your tax and National Insurance are recorded against you. See how National Insurance works.
Years of contributions build up towards the State Pension and some benefits. See State Pension explained.
If you start work before you get your number, your pay may be taxed on an emergency tax code until things are sorted out. See tax codes explained and how to read your payslip.

Common mistakes

Giving your NI number to people who contact you out of the blue. Genuine requests come from your employer, HMRC or the Department for Work and Pensions.
Waiting for the number before applying for a job. You can usually start work first if you can prove your right to work.

Where to learn more

This guide is for general information only and is not immigration, legal, tax or financial advice. Your own situation depends on your immigration permission and circumstances, and rules can change, so check the official pages and get advice from a regulated adviser if you are unsure.