What Is Your Social Security Number?
The codes that we commonly refer to as our SSAN, EIN or KTN aren’t numbers as much as each is a textual code. In the case of the SSAN the code itself is composed of three separate numerals that once had real meaning.
While Cambridge English Dictionary primarily defines a number as “a unit or its symbol that forms part of a system of counting and calculating, and that represents an amount or position in a series,” we think it’s simpler: a number is a symbol that can be added or multiplied. These account numbers can do neither.
Interestingly, there once was real information embedded in the SSAN and EIN codes. Until 2011 and 2001, respectively (which are actual numbers indicating position in a sequence), the first digits identified the geographic area in which the account was created. “570” and “15” denoted California, for instance. SSAN’s two-digit central code initially indicated the filing cabinet area in which the file was stored. Later, it became the computer memory location. Today, it’s only a filter needed to help order, filter and differentiate the accounts specified by the final four digits. Surprisingly, the codes do not have built-in verification or check numbers. Twins whose parents request accounts will typically be awarded sequential numbers.
The Social Security Administration has has issued more than 400 million codes so far and has nearly 400 million codes remaining available for issuance, so the system will likely run out of money long before it runs out of cards.
(See How to “Reduce Social Security Account Number (SSAN) to Final Four Digits“)
