A National Insurance number (NI number) is the reference number used by HM Revenue & Customs (HMRC) for recording your contributions towards the state pension and some other state benefits. Employers must enter your NI number on the form they send to HMRC at the end of each tax year to report the amount of tax you have paid and the amount of National Insurance Contributions (NICs) that you and your employer have paid.

The Department for Work and Pensions (DWP) issues an NI number to every child as soon as a Child Benefit claim is made for the child. At that time, the number is known as a Child Reference Number (CRN). Before they leave school, all young people in the UK are issued with a plastic card that shows their CRN, but now known as the NI number. A new card may be issued subsequently if your name changes on marriage, or if you do not have an NI number and apply for one. An NI number card cannot be used as an identity card.

Guidance on obtaining an NI number is provided by HMRC at http://www.hmrc.gov.uk/nic/ynino.htm and by the Department for Work and Pensions (DWP) at http://www.dwp.gov.uk/...asp.

To obtain an NI number, HMRC's guidance tells you to contact your local Social Security Office. These offices are called Jobcentre Plus offices. You can find the address and phone number of your nearest office at http://www.jobcentreplus.gov.uk/JCP/Aboutus/...aspx.

When you have found the details of your local office, you should contact it by telephone and ask for an appointment to be interviewed for an NI number. Information about the "evidence of identity interview" is available at http://www.dwp.gov.uk/lifeevent/benefits/ni_number.asp. At the interview you will be asked to provide evidence of your identity. The kinds of documents that are acceptable are listed in booklet GL25, available at http://www.dwp.gov.uk/publications/dwp/2003/gl25_oct.pdf.

The HMRC department responsible for creating new National Insurance records is the NI Registrations section of the National Insurance Contributions Office. If you need to discuss your situation, you can telephone the HMRC Registrations Helpline, on 08459 1 57006, open Monday to Friday 8:00am to 5:00pm.

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