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".
Social security in Sweden
Social security in Sweden is one of the parts of the Swedish welfare system and consists of various social insurances handled by the National Agency for Social Insurance (Swedish; Försäkringskassan), and also welfare given out on a need basis by local municipalities. They are the main conduits for redistribution of approximately 48% of the Swedish GDP in the form of taxed income.