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".
State Earnings-Related Pension Scheme
The State Earnings Related Pension Scheme (SERPS), originally known as the State Earnings Related Pension Supplement, was a UK Government pension arrangement, to which employees and employers contributed between 6 April 1978 and 5 April 2002, when it was replaced by the State Second Pension.