The Payment Card Industry Data Security Standard (PCI) applies to any organization that accepts credit and bank debit cards as payment for goods and services. In other words, the standard covers businesses ranging from mega-retailers and airlines to local dry cleaners and newsstands. PCI breaks down compliance into levels based on the number of transactions processed annually by a merchant. For instance, expectations are higher for Wal-Mart because it has more resources than Joe?s Main Street Barbershop. Below are the four PCI DSS levels.