AAA Merchant Solutions

The payment card industry defines an ISO as an organization or individual that is not an Association member (meaning not a Visa or MasterCard member bank), but which has a bank card relationship with an actual Association member. Such a relationship can involve various things, such as acquiring or issuing functions, soliciting new customers, arranging for terminal purchases or leases, providing customer service, soliciting cardholders, etc

An ISO is sometimes referred to as a Member Service Provider (MSP), although the definitions of these two terms are not always synonymous. The easiest way to explain the difference between the two is that MasterCard refers to its ISOs as MSPs, defining a Member Service Provider as “a non-member that is registered by the Corporation [MasterCard] as an MSP to provide Program Services to a member, or any member that is required to register, in the Corporation’s sole discretion, and has been registered as an MSP to provide Third Party Processor Program Services to another member.” Members of MasterCard and Visa must register all of their ISOs / MSPs with the applicable Association.