National Insurance (NI) is a contribution system that entitles citizens of United Kingdom to certain social benefits, such as insurance, pension and protection from unemployment. Each individual who pays into this system is assigned a NI number, which identifies you with available social benefits. If you have lost or forgotten your NI number or NI number card, you must contact that appropriate governmental department in order to get your NI number and a new card.
Contact your local Inland Revenue National Insurance Contributions office. You can find the listings for local offices in the telephone book, or online at the resource provided by the HM Revenue and Customs website.
Speak to an official at the Inland Revenue National Insurance Contributions office and tell him or her that you have forgotten your NI number and you cannot find your NI card. You will need to set up an appointment time for a personal interview with a department official.
Take additional identification documents, such as a passport, birth certificate and identification card with you to the interview. The interviewer needs to establish your identity before reissuing you an NI card, which contains your NI number.
Keep your NI number card in a safe and secure location once you have received your new card.