Who is classified as a Service Provider under PCI DSS?

The classification of a Service Provider under PCI DSS specifically includes any business that processes, stores, or transmits cardholder data on behalf of another entity. This definition aligns with the intent of PCI DSS, which focuses on protecting payment card data throughout the transaction process. Service Providers are integral to the payment ecosystem, as they handle sensitive payment information for merchants or other entities.

In this context, processing, storing, or transmitting cardholder data involves direct interaction with payment card information, and therefore these entities must adhere to PCI DSS requirements to ensure the security and privacy of this data. By complying with PCI DSS, these businesses help secure the payment card ecosystem and protect cardholders from data breaches and fraud.

Other options, while related to financial transactions, do not encompass the full responsibility associated with handling cardholder data. For example, businesses managing payment networks or issuing credit cards may play important roles in transactions, but they do not necessarily handle cardholder data on behalf of others in the same manner as defined for Service Providers. Similarly, entities that only provide merchant accounts may not engage directly with the critical functions of processing, storing, or transmitting cardholder data. Thus, option C is the most accurate representation of what constitutes a Service Provider per PCI DSS guidelines.