ISO/IEC 27017 standard defines the requirements for an information security management system (ISMS). Note that the entire organization is not necessarily affected by the standard, because it all depends on the scope of the ISMS. The scope could be limited by the provider to one group within an organization, and there is no guarantee that any group outside of the scope has appropriate ISMSs in place. It is up to the auditor to verify that the scope of the engagement is "fit for purpose." As the customer, you are responsible for determining whether the scope of the certification is relevant for your purposes.