The score is based on trade experiences reported by vendors and is derived from a weighted average of a company’s combined individual payment experiences (larger invoice amounts weigh heavier in the overall index). A company needs at least three pieces of trade reported by at least two different vendors in order to have a PAYDEX. It’s based on a scale of 1-100 (where 100=best and 0=worst). A score of 80 is the benchmark; it means that a company pays its bills on time, or promptly, according to its suppliers.