Social Security number (United States)

Missing image
United States Social Security Card
In the United States, a Social Security number (SSN) is a number issued to citizens, permanent residents, and temporary (working) residents. It is issued to an individual by the Social Security Administration of the government of the United States. Ostensibly, its primary purpose is tracking working individuals for taxation purposes and to track Social Security benefits. However, in recent years, the SSN has become a de facto national identification number.


The first SSNs were issued by the Social Security Administration in November of 1936. By the end of 1937, over 37 million numbers had been issued.

Before the 1980s, people often did not have a Social Security number until the age of about 15, since they were used for tax purposes and those under that age seldom had remunerative employment. During the 1980s, American taxation law was altered so that individuals without Social Security numbers could not be claimed as dependents on tax returns. Since then, parents have often applied for Social Security numbers for their children as soon as they were born.

Purpose and use

The original purpose of this number was to administer the Social Security program, but it has come to be used also as a "primary key" (a de facto national ID number) for individuals within the United States. This is a major example of functionality creep. Payroll, university student records, credit records, and driver's licenses are frequently indexed by Social Security number. The U.S. military has used the Social Security number as an identification number for all servicemembers since 1968. As a result, disclosure and processing of these numbers is of major concern to privacy advocates.

The SSN is frequently used by those involved in identity theft, since it is interconnected with so many other forms of identification, and because it is generally required by financial institutions to set up bank accounts, credit cards, and obtain loans.


The Social Security number is a nine-digit number in the format "NNN-NN-NNNN." The number is divided into three parts.

  • The first three digits are the area number. If the Social Security number was assigned before March 1972 (when Social Security cards were issued by local offices) the area number reflects the State where the Social Security number was applied for. Since March 1972, Social Security numbers have been issued through a central office. For the most part (there are exceptions), the area is determined by where the individual applied for the SSN (before March 1972) or resided at time of application (since March 1972). As the areas assigned to a locality are exhausted, new areas from the pool are assigned. This has caused some states to have noncontiguous groups of Areas.
  • The middle two digits are the group number. They have no special geographic or data significance but merely serve to break the number into conveniently sized blocks for orderly issuance.
  • The last four digits are serial numbers. They represent a straight numerical sequence of digits from 0001-9999 within the group.

Valid SSNs

Currently, a valid SSN cannot have the first three digits (the area number) above 772, the highest area number which the Social Security Administration has allocated.

There are also special numbers which will never be allocated:

  • Numbers with all zeros in a digit group (000-xx-xxxx, xxx-00-xxxx, xxx-xx-0000).
  • Numbers of the form 666-xx-xxxx, probably due to the potential controversy (see Number of the Beast). Though the omission of this area number is not acknowledged by the SSA, it remains unassigned.
  • Numbers from 987-65-4320 to 987-65-4329 are reserved for advertising use.

Finally, the Administration publishes the highest group number used for each area number. Since these are allocated in a regular (if unusual) pattern, it may be possible to identify an invalid SSN by accidental inclusion of an invalid group number. Despite these measures, fraudulent non-existent SSNs are possible, because of the lack of a check digit.

SSNs invalidated by use in advertising

SSNs used in advertising have rendered those numbers invalid. One famous instance of this occurred in 1938 when the E. H. Ferree Company in Lockport, New York decided to promote its product by showing how a Social Security card would fit into its wallets. A sample card, used for display purposes, was placed in each wallet, which was sold by Woolworth and other department stores across the country. The wallet manufacturer's vice president thought it would be clever to use the actual SSN of his secretary, Hilda Whitcher.

Even though the card was printed in red (the real card is printed in blue), was half the size of the real card, and had "Specimen" printed across the front, many people utilized the SSN. Over time the number that appeared (078-05-1120) was claimed by over 40,000 people as their own. The SSA initiated an advertising campaign stating that it was incorrect to use the number. (Hilda Whitcher was issued a new SSN.) However, the number was found to be in use by 12 individuals as late as 1977.

See also

External links


  • Art and Cultures
    • Art (
    • Architecture (
    • Cultures (
    • Music (
    • Musical Instruments (
  • Biographies (
  • Clipart (
  • Geography (
    • Countries of the World (
    • Maps (
    • Flags (
    • Continents (
  • History (
    • Ancient Civilizations (
    • Industrial Revolution (
    • Middle Ages (
    • Prehistory (
    • Renaissance (
    • Timelines (
    • United States (
    • Wars (
    • World History (
  • Human Body (
  • Mathematics (
  • Reference (
  • Science (
    • Animals (
    • Aviation (
    • Dinosaurs (
    • Earth (
    • Inventions (
    • Physical Science (
    • Plants (
    • Scientists (
  • Social Studies (
    • Anthropology (
    • Economics (
    • Government (
    • Religion (
    • Holidays (
  • Space and Astronomy
    • Solar System (
    • Planets (
  • Sports (
  • Timelines (
  • Weather (
  • US States (


  • Home Page (
  • Contact Us (

  • Clip Art (
Personal tools