SAQ A is applicable to which type of merchants?

The applicability of SAQ A (Self-Assessment Questionnaire A) is specifically designed for Card-Not-Present (CNP) merchants who only accept credit card payments through e-commerce channels and do not store, process, or transmit cardholder data on their systems. This is important because SAQ A is intended for merchants that have completely outsourced their payment functions to validated third-party service providers, thereby minimizing their own scope for PCI DSS compliance.

CNP merchants typically conduct transactions online and are not involved in the physical acceptance of cards. By utilizing third-party payment solutions that handle all payment data securely, these merchants can meet the criteria set out in SAQ A. This focus on minimizing cardholder data handling helps reduce security risks and simplifies compliance efforts since these merchants are not managing sensitive payment information directly.

In contrast, the other options involve entities that either interact with cardholder data in a direct manner (like face-to-face retailers) or engage in financial transactions through direct channels (like online banking services), making them ineligible for SAQ A and requiring different compliance approaches under the PCI DSS framework.