Obtaining a national insurance number

This section of the website is focused on obtaining a national insurance number, it covers:


  • Basics

  • Why do I need it?

  • How do I get one?

Get started below.

The government department of HM Revenue and Customs issues national insurance numbers to people living in the UK. You are given a National Insurance number to make sure your national insurance contributions and tax are recorded against your name only.  It is sometimes called an NI number. It is best to get a national insurance number as soon as possible and most people get a national insurance number just before they turn 16 year old.


It is made up of letters and numbers and never changes.

Why do you need it?


You will need a national insurance number for the following:


  • If you get a job

  • If you want to apply for benefits

  • If you want to apply for a student loan


There are other times you will also need it.


You can start a job without a national insurance number but will need to prove that you have the right to work and you will need to provide a national insurance number to get paid.


How do I get one?


Children who are looked after by local authorities do not automatically get sent a national insurance number.  


Your social worker can apply for a national insurance number for you. They can apply when you are 15 years and 9 months old.  They need to explain in a letter that they are applying for a number for a looked after child and they must give your contact details.

Your social worker must also include:

  • a statement that they're a social worker applying for a National Insurance number for a looked after child

  • your full name

  • any previous names you have used

  • your date of birth

  • the date you went into care

  • your current residential address

  • the contact details of the social worker who has written the letter

If possible, the letter should also include:

  • any previous addresses (such as your parent’s old address or your last address before you were taken into care)

  • a photocopy of any of the following:

    • your birth certificate

    • your Care Order

    • the ID page of your passport

The application must be sent to:


PT Operations North East England

HM Revenue and Customs



HMRC will then send you a letter confirming your national insurance number. 

What if I lose my NI number?

The first place to look is on any existing documents that you may have. Your NI number can usually be found on pay slips, P60, P45 or on any letters about tax, pensions and benefits.  If you still can't find it you can obtain your NI number by one of the options below:

Option 1 via Personal Tax Account – quickest method if you have the right identification

You can create a personal tax account using a Government Gateway Account this will allow the you to see your NI number.


Please see link below on how to create this and set it up.


You will need a UK address and UK Passport.


If you do not have these then you would need to contact HMRC by phone as mentioned below in option 2.



Option 2 Via Telephone


Telephone HMRC - 0300 200 3500

HMRC will speak to the you directly and ask some security questions. They will then send your national insurance number in the post.


If you try this service and cannot answer the security questions, you will need to fill in the form below in Option 3 and send it off in the post.


Option 3 via CA5403 form


If you cannot get your NI number by either of the above 2 methods you will need to print this form off. Complete it and then send off in the post.