Per the FICO scoring system, the lowest possible score is 350, however even FICO has noted that this score is never actually seen. There are other scoring models out there, and the lowest score ranges from 350-450 (but they also have potentially higher scores on the other end of the range). As a note, Congress itself has investigated the scoring system, and per interviews with many "experts" there seems to be a considerable lack of clarity on the subject.
