What may partially outsourced E-commerce merchants using a third-party website for payment processing fill out?

For partially outsourced e-commerce merchants that utilize a third-party website for payment processing, the appropriate choice is SAQ-A EP. This Self-Assessment Questionnaire is specifically designed for businesses that have outsourced their payment processing to a third-party service provider, meaning the payment transactions occur on the provider's platform rather than directly on the merchant’s website.

SAQ-A EP allows these merchants to confirm they do not store, process, or transmit cardholder data on their own systems. However, it does apply in situations where the merchant may still need to manage some elements related to payment processing, such as handling redirects to a third-party payment processor or having limited commerce capabilities on their site.

In comparison, other options are tailored to different scenarios. SAQ-B is suitable for merchants that do not store cardholder data but do process payments through standalone, dial-out terminals. SAQ-C is intended for merchants that handle cardholder data via a connected payment system but do not store it—a situation that does not apply to those fully outsourcing payments like in SAQ-A EP. Finally, SAQ-D encompasses all types of merchants and is used when a merchant stores, processes, or transmits cardholder data across their systems, which is not applicable for partially outsourced setups.