A National Insurance number (NI number) is a unique identification number used by the UK government to track an individual’s contributions to the National Insurance system. It is used to calculate how much National Insurance contributions an individual has paid, and to determine their entitlement to certain benefits and services, such as the State Pension and Jobseeker’s Allowance.
It is important to know your NI number, as you may need it for a variety of purposes, such as applying for a job, claiming benefits, or opening a bank account. You can check your NI number online using the government’s website, or by calling the National Insurance helpline.