Service Providers are a collective term for third-party processors, data storage facilities, and any organization that facilitates, stores, transmits, or processes credit card transactions. Both issuers and acquirers must use, and are responsible for ensuring that their merchants use service providers that are compliant with the PCI Data Security Standard (DSS). Although there may not be a direct contractual relationship between service providers and acquirers, card brand clients are responsible for any liability that may occur as a result of non-compliance. Service Providers include Authorized Processors, Third Party Processors, Gateway Providers, and any other that provider point of sale equipment, software, or other payment processing solutions or services.

The various card-specific service provider level descriptions and requirements can be found at the following:

VISA Service Provider
MasterCard Service Provider
Discover Service Provider
American Express Service Provider
JCB-Global Merchant