When it comes to the back end of credit card processing, most people have no idea that there is a complex and complicated system creating the infrastructure for the entire credit card processing industry. Processing platforms are the back-end networks that merchant’s credit card terminals and software connect to. These networks enable businesses to process credit cards.

This diagram is a very basic (and incomplete) model of the back-end of credit card processing. The main processing platforms that businesses in the US deal with are listed. Green denotes the most commonly used platforms, and sub-platforms, and the Orange denotes some of the larger ISO’s and providers.