National Insurance number
The National Insurance number is used as a reference number in the Pay As You Earn system, and also by the self-employed. It is also used in applications for Individual Savings Accounts (ISAs), to check that an individual has opened only one ISA in a tax year.
Ministry of Social Security (UK)
In 1966, the Supplementary Benefits Commission (part of the National Assistance Board) was merged with the Ministry of Pensions and National Assistance to form the new Ministry of Social Security, as part of the Ministry of Social Security Act 1966.