This blog is written by Mr. Waheed Ahmed, Associate Audit Services.



The objective of ISA 620 is to allow the auditor to:

  • decide whether to use the work of an expert, and
  • assess whether that work is adequate.

Assessing the need for an expert

There is a cost attached to the use of an expert by the auditors. The expert will charge a fee for the professional service he provides. The use of an expert should therefore be evaluated on a cost/benefit basis.

When deciding whether he needs to use an expert to assist him in obtaining sufficient appropriate evidence, the auditor should consider such factors as:

  • the nature, significance and complexity of the matter ;
  • the risk of material misstatement ; and
  • the availability of alternative sources of audit evidence.

Assessing the work of an expert

ISA 620 requires the auditor to apply the procedures set out below when using the work of an expert. The auditor should:

  • assess the competence, capabilities and objectivity of the expert in one or more of the following ways:

– Personal experience with previous work of that expert.

– Discussions with that expert.

– Discussions with other auditors or others who are familiar with that expert’s work.

– Knowledge of that expert’s qualifications, membership of a professional body or industry association, license to practice, or other forms of external recognition.

– Published papers or books written by that expert.

  • obtain an understanding of the expert’s field of expertise, sufficient to allow the auditor to determine the nature, scope and objectives of the expert’s work and evaluate the adequacy of that work
  • agree terms of engagement with the expert, including:
  • the nature, scope and objectives of the expert’s work
  • the respective responsibilities of the expert and the auditor
  • the form of the expert’s report
  • confidentiality requirements
  • evaluate the adequacy of the expert’s work, including the:
  • reasonableness of the expert’s conclusions
  • consistency of those conclusions with other audit evidence
  • reasonableness of significant assumptions and methods used
  • relevance, completeness and accuracy of source data.

Generally, the auditor is assessing whether the expert’s work constitutes sufficient and appropriate audit evidence.

If the auditor decides that the work of the expert is not adequate he is required to:

  • agree additional work with the expert, or
  • perform other appropriate additional audit procedures.

The auditor has sole responsibility for the audit opinion issued and this is not reduced in any way by his use of an expert. Therefore he should not refer in his report to the use of an expert, unless that is required by law or regulation. Even then, or if the auditor refers to the expert’s work in his report because it is relevant to an understanding of a modified opinion, then he must make it clear that such a reference does not reduce his responsibility for that opinion in any way.

Waheed Ahmed