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".
Welfare Reform Act 2007
The Welfare Reform Act 2007 (c.5) is an Act of the Parliament of the United Kingdom which alters the British social security system. A number of sections come into force two months after royal assent and the first commencement order made under the Act specified that section 31 came into force on 1 November 2007.