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 (United States)
A side effect of the Social Security program in the United States has been the near-universal adoption of the program's identification number, the Social Security number, as the "de facto" U.S. national identification number. The social security number, or SSN, is issued pursuant to section 205(c)(2) of the Social Security Act, codified as . The government originally stated that the SSN would not be a means of identification, but currently a multitude of U.S. entities use the Social Security number as a personal identifier. These include government agencies such as the Internal Revenue Service, the military as well as private agencies such as banks, colleges and universities, health insurance companies, and employers.