Short for System Identification Number, one’s SIN is a unique number used for everything from census data to background checks. It performs more or less the same role as the 20th century social security number, but with virtually no taxation and more or less non-existent government subsidy programs, it does not denote anything beyond a passing relationship with UCAS national citizenship.
To receive a SIN, one usually must either work for a corporation, the government, or have attended some kind of formal school run by one of the two. While infants can be registered with a SIN, most working class parents don’t find an easy way to do the requisite paperwork, leaving that to the schools.
Those without SINs, often called the SINless, are mostly poor, sometimes criminally poor, and live in either Redmond or Puyallap Barrens. In those sense urban jungles it is rather easy to never encounter a government official or corporate officer in one’s life and thus never be officially registered.
The population of Seattle is about 6 million by the reckoning of the 2070 census. But some estimate that there may be as many as 2 million SINless living in the metroplex limits, a staggering number when one considers how government and corporate interests use SIN to calculate much of the financial, food, shelter and educational facilities of the city.
The SINless, in addition to not being recognized as existing, cannot open a bank account, get through certain corporate or government checkpoints or even make purchases as many stores. This has created a vast network of off the grid businesses that accept unregistered credsticks or even barter for basic goods.
Of course, for runners, having a SIN can be a liability. Some advanced scanners read one’s genome and can determine identity based on the SIN registry database. This means that most runners scrub their SINs before entering seriously into the business. Once lost, a SIN cannot be replaced, so scrubbing it can often lead to quality of life complications.