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 Administration
The United States Social Security Administration (SSA) is an independent agency of the U.S. federal government that administers Social Security, a social insurance program consisting of retirement, disability, and survivors' benefits. To qualify for most of these benefits, most workers pay Social Security taxes on their earnings; the claimant's benefits are based on the wage earner's contributions. Otherwise benefits such as Supplemental Security Income (SSI) are given based on need.