National Insurance number
The National Insurance number is a number used in the United Kingdom in the administration of the National Insurance or social security system. It is also used for some purposes in the UK tax system. The number is described by the United Kingdom government as a "personal account number".
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.