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.
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.