Find a lost National Insurance number

Man looking for National Insurance number on computer

If you live in the UK, you should automatically get a National Insurance (NI) number just before your 16th birthday. Everyone who works in the UK has to pay National Insurance contributions and an employer will need to know your NI number before you can start a job.

This unique reference number allows HMRC to keep records of your tax and National Insurance contributions. It also ensures that you get the benefits - including the state pension - that you are entitled to.

How to find your National Insurance number

HM Revenue & Customs no longer issues plastic NI cards. If you have lost or forgotten your NI number, you can find it on your payslip, P60, or on any letters sent to you by HMRC relating to tax, pensions and benefits. You can also view it on your personal tax account if you've registered for one.

If you cannot register for a personal tax account and you still can't find your NI number, you can:

  • fill in and return form CA5403 to HMRC together with 2 identification documents
  • phone the National Insurance numbers helpline on 0300 200 3500

HMRC will not provide your National Insurance number over the phone – it will be posted to you.

If you didn't get an NI number when you turned 16, you can also phone the National Insurance numbers helpline on 0300 200 3500.

How to get a new National Insurance number

If you're over 20 and you haven't got a NI number, you need to apply for a National Insurance number. If you need help, call the National Insurance number application helpline on 0800 141 2079.

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