Your National Insurance number is a nine-digit reference made up of letters and numbers in the format QQ123456A. Please enter the reference with no spaces.
The number can be found on your National Insurance card, if you have been sent one. If you are an employee, you can also find your National Insurance number on your payslip or P60 (certificate of pay and tax deducted). You will also find it on most correspondence from HM Revenue & Customs.
You must have a National Insurance number before you can register for Self Assessment. If you do not have a UK National Insurance number you must contact the Department for Work and Pensions on Tel 0845 600 0643.