AU-C Section 220.25-26: Documentation of Quality Control

AU-C Section 220.25-26 says:


".25 The auditor should include in the audit documentation the following:(Ref: par. .A35)

•  Issues identified with respect to compliance with relevant ethical requirements and how they were resolved
•  Conclusions on compliance with independence requirements that apply to the audit engagement and any relevant discussions with the firm that support these conclusions
• Conclusions reached regarding the acceptance and continuance of client relationships and audit engagements
• The nature and scope of, and conclusions resulting from, consultations undertaken during the course of the audit engagement (Ref:par. .A36) 

.26 The engagement quality control reviewer should document, for the audit engagement reviewed 

•  that the procedures required by the firm's policies on engagement quality control review have been performed;
• the date that the engagement quality control review was completed; and
• that the reviewer is not aware of any unresolved matters that would cause the reviewer to believe that the significant judgments that the engagement team made and the conclusions it reached were not appropriate" 

AU-C Section 230 addresses the auditor's responsibility to prepare audit documentation for an audit of financial statements. Section 230 also states that it is neither necessary nor practicable for the auditor to document every matter considered, or professional judgment made, in an audit.

Documentation of consultations with other professionals involving difficult or contentious matters that is sufficiently complete and detailed contributes to an understanding of

•  the issue on which consultation was sought and
•  the results of the consultation, including any decisions made, thebasis for those decisions, and how they were implemented.

https://www.aicpa.org/content/dam/aicpa/research/standards/auditattest/downloadabledocuments/au-c-00220.pdf