If expertise in a field other than accounting or auditing is necessary to obtain sufficient appropriate audit evidence, the auditor shall determine whether to use the work of an auditor’s expert. (Ref: Para. A4-A9)

The nature, timing and extent of the auditor’s procedures with respect to the requirements in paragraphs 9-13 of this Auditing Standard will vary depending on the circumstances. In determining the nature, timing and extent of those procedures, the auditor shall consider matters including: (Ref: Para. A10)

1. The nature of the matter to which that expert’s work relates;
2. The risks of material misstatement in the matter to which that expert’s work relates;
3. The significance of that expert’s work in the context of the audit;
4. The auditor’s knowledge of and experience with previous work performed by that expert; and
5. Whether that expert is subject to the auditor’s firm’s quality control policies and procedures. (Ref: Para. A11-A13)

The auditor shall evaluate whether the auditor’s expert has the necessary competence, capabilities and objectivity for the auditor’s purposes.  In the case of an auditor’s external expert, the evaluation of objectivity shall include enquiry regarding interests and relationships that may create a threat to that expert’s objectivity. (Ref: Para. A14-A20)

The auditor shall obtain a sufficient understanding of the field of expertise of the auditor’s expert to enable the auditor to: (Ref: Para. A21-A22)

1. Determine the nature, scope and objectives of that expert’s work for the auditor’s purposes; and
2. Evaluate the adequacy of that work for the auditor’s purposes.

The auditor shall agree, in writing when appropriate, on the following matters with the auditor’s expert: (Ref: Para. A23-A26)

1. The nature, scope and objectives of that expert’s work; (Ref: Para. A27)
2. The respective roles and responsibilities of the auditor and that expert; (Ref: Para. A28- A29)
3. The nature, timing and extent of communication between the auditor and that expert, including the form of any report to be provided by that expert; and (Ref: Para. A30)
4. The need for the auditor’s expert to observe confidentiality requirements. (Ref: Para. A31)

The auditor shall evaluate the adequacy of the auditor’s expert’s work for the auditor’s purposes, including: (Ref: Para. A32)

1. The relevance and reasonableness of that expert’s findings or conclusions, and their consistency with other audit evidence; (Ref: Para. A33-A34)
2. If that expert’s work involves use of significant assumptions and methods, the relevance and reasonableness of those assumptions and methods in the circumstances; and (Ref: Para. A35-A37)
3. If that expert’s work involves the use of source data that is significant to that expert’s work, the relevance, completeness, and accuracy of that source data. (Ref: Para. A38-A39)

If the auditor determines that the work of the auditor’s expert is not adequate for the auditor’s purposes, the auditor shall: (Ref: Para. A40)

1. Agree with that expert on the nature and extent of further work to be performed by that expert; or
2. Perform additional audit procedures appropriate to the circumstances.

The auditor shall not refer to the work of an auditor’s expert in an auditor’s report containing an unmodified opinion unless required by law or regulation to do so.  If such reference is required by law or regulation, the auditor shall indicate in the auditor’s report that the reference does not reduce the auditor’s responsibility for the auditor’s opinion. (Ref: Para. A41)

If the auditor makes reference to the work of an auditor’s expert in the auditor’s report because such reference is relevant to an understanding of a modification to the auditor’s opinion, the auditor shall indicate in the auditor’s report that such reference does not reduce the auditor’s responsibility for that opinion. (Ref: Para. A42)