National insurance number

Definition: Your National Insurance number is your own personal account number.

  • It is unique to you and you keep the same one all your life. Your number never changes, under any circumstance
  • Your NI number is made up of 2 letters, six numbers and then one letter (which is always A, B ,C or D)
  • It makes sure that the National Insurance contributions and tax you pay are properly recorded against your name
  • Your number makes sure you pay the correct amount in line with your circumstances
  • It acts as a reference number when communicating with the Department for Work and Pensions and HM Revenue & Customs (HMRC)
  • You typically receive your NI number through the post in between the ages of 15-16
  • You can find your number on previous payslips or letters about tax, pensions and benefits
  • If you loose you number, call the National Insurance inquiries helpline on 0300 200 3500 (lines are open 8am to 5pm, Monday to Friday)

For further information on National Insurance visit the RSC website