All service providers are responsible for meeting expected to meet  PCI DSS requirements for their environments as applicable to the services offered to their customers. In addition, PCI DSS Appendix A1: Additional PCI DSS Requirements for Multi-Tenant Service Providers appliesincludes requirements specific to multi-tenant service providers, which is a type of third-party service provider (TPSP) that offers various shared services to merchants and other service providers.

Appendix A1 for Multi-Tenant Service Providers applies to service providers with customers in shared services environments, where customers manage their own environment or have administrative control over their own segment.

Multi-tenant service providers offer various shared services to merchants and other service providers, where customers share system resources (such as physical or virtual servers), infrastructure, applications (including Software as a Service (SaaS)), and/or databases. Services may include, but are not limited to, hosting multiple entities on a single shared server, providing e-commerce and/or “shopping cart” services, web-based hosting services, payment applications, various cloud applications and services, and payment gateway and processor services offered in a shared environment. *

Int is not the intent that all or even most TPSPs are categorized as multi-tenant service providers. For example, the following are not considered multi-tenant service providers and are not subject to Appendix A1:

TPSPs that offer a single, unified environment where customers access only their own data through a common platform, and the provider manages all access and infrastructure.
TPSPs that offer only shared data center services (often called co-location or "co-lo" providers), where equipment, space, and bandwidth are available on a rental basis.
TPSPs with servers that are dedicated to a single customer.

Note that all other applicable PCI DSS v4.0, the title of Appendix A1 was updated to “Additional PCI DSS Rrequirements for Multi-Tenant Hosting Providers” to support the do apply to the abroader range of technologies used to provide shared services. In PCI DSS v3.2.1, Appendix A1 was entitled ‘Additional PCI DSS Requirements for Shared Hosting Providers’.

Service providers that offer only shared data center services (often called co-location or “co-lo” providers), where equipment, space, and bandwidth are available on a rental basis, are not considered service providers for purposes of Appendix A1 in either PCI DSS v3.2.1 or PCI DSS v4.0. In addition, these requirements for multi-tenant service providers are not applicable when servers are dedicated to a single customer (but all other applicable PCI DSS requirements do apply).

For additional information and applicable requirements for thesove TPSPs, refer to PCI DSS Appendix A1: Additional PCI DSS Requirements for Multi-Tenant Service Providers.

Whether a service provider is required to validate PCI DSS compliance is determined by the organizations that manage compliance programs (for example, an acquirer, payment brand, or other entity). Entities should always contact the entity that manages their compliance program directly to determine their compliance requirements. Contact details for the payment brands can be found in FAQ #1142: How do I contact the payment card brands?

* For additional information and applicable requirements for these TPSPs, refer to PCI DSS Appendix A1: Additional PCI DSS Requirements for Multi-Tenant Service Providers.