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Document National Insurance (NI) number - What is this and where can it be obtained from?

The National Insurance (NI) number is a number used in the United Kingdom in the administration of the National Insurance or social security system. It is also used for some purposes in the UK tax system, it is the only number allocated to almost every adult resident of the country.

Each NI Number is made up of 9 digits shown in a 2-2-2-1 format, usually as follows:

(This is an example only.)

 
AB 12 34 56 C


Obtaining your National Insurance number

You can find your NI number on your payslip, P60 or tax return.

If you do not know your NI number or are unable to find it, you can either:
  • fill in form CA5403 and send it to the address on the form
     
  • phone the National Insurance numbers helpline on 0300 200 3500 if you are calling from the UK or 0044 191 203 7010 if you are calling from outside of the UK.
The National Insurance numbers helpline is open 8am to 5pm, Monday to Friday. They cannot provide you with your NI number over the telephone, they will provide it in writing.

Please see the website for further information.
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NI, National Insurance, number, where, obtained