Updated as of January 1, 2018, this guide includes relevant guidance contained in applicable standards and other technical sources. It explains the relationship between a service organization and its user entities, provides examples of service organizations, describes the description criteria to be used to prepare the description of the service organization's system, identifies the trust services criteria as the criteria to be used to evaluate the design and operating effectiveness of controls, explains the difference between a type 1 and type 2 SOC 2 report, and provides illustrative reports for CPAs engaged to examine and report on system and organization controls at a service organization. It also describes the matters to be considered and procedures to be performed by the service auditor in planning, performing, and reporting on SOC 2 and SOC 3 engagements. New to this edition are: Updated for SSAE No. 18 (clarified attestation standards), this guide has been fully conformed to reflect lessons learned in practice Contains insight from expert authors on the SOC 2 working group composed of CPAs who perform SOC 2 and SOC 3 engagements Includes illustrative report paragraphs describing the matter that gave rise to the report modification for a large variety of situations Includes a new appendix for performing and reporting on a SOC 2 examination in accordance with International Standards on Assurance Engagements (ISAEs) or in accordance with both the AICPA's attestation standards and the ISAEs