Relying on an expert's work
How an audit team evaluates and documents a valuer's, actuary's or other expert's work under ISA 620 and ISA 500, and records the expert in Achekam.
By Achekam · · 5 min read · For Accountants & audit firms in South Africa, Nigeria, Kenya
The investment property is carried at a valuation signed by a registered valuer. The pension obligation comes from an actuary's report. The stage of completion on a construction contract rests on a quantity surveyor's certificate. In each case the largest judgement in the statements was made by someone outside the audit team, in a discipline the team does not practise, and the temptation is to staple the report to the file and move on.
The standards do not allow that, and inspectors notice when it happens. An expert's report is evidence only once the auditor has assessed who wrote it, what they were asked to do and whether their conclusions make sense. This article walks through that assessment and how to keep a record of it in Achekam.
The auditor's expert or management's expert
Start by deciding whose expert this is, because two different standards apply.
| Auditor's expert | Management's expert | |
|---|---|---|
| Engaged by | The audit firm (or a specialist inside it) | The client |
| Standard | ISA 620 | ISA 500 |
| Purpose | Helps the auditor obtain evidence | Helps the client prepare its statements |
| Typical example | A valuer the firm appoints to test the client's valuation | The valuer whose figure the client booked |
Both need evaluating. The difference is the depth and the control the auditor has: you can set the terms of your own expert's work, while you can only understand and assess the terms the client set for its expert. The full text of ISA 620 and ISA 500 is in the IAASB's 2026 Handbook of international quality management, auditing and assurance pronouncements, which contains every International Standard on Auditing.
Competence, capability and objectivity
For either kind of expert, the auditor evaluates three things.
- Competence: the nature and level of expertise. Professional registration, qualifications and experience in this particular kind of asset or obligation matter more than general standing. A residential valuer valuing a specialised factory is a warning sign.
- Capability: whether the expert can actually do this job, given their time, resources and access to the information they need.
- Objectivity: interests and relationships that could threaten it. For management's expert, ask how they are paid, whether they have other work from the client, and whether they are related to anyone at the client. For your own expert, include the same questions about the client.
Write the evidence for each conclusion on the paper, not just the conclusion. "Registered valuer, competent" is not enough; "registration confirmed against the professional body's register on a stated date, with the evidence attached" is.
Agreeing the scope of the expert's work
For an auditor's expert, ISA 620 asks for agreement, in writing where appropriate, on the nature, scope and objectives of the work, the respective roles of the auditor and the expert, how and when they will communicate (including the form of any report), and confidentiality. A short engagement letter with the expert covers all of it.
For management's expert, obtain and read the terms the client agreed. A valuation prepared for a bank's lending decision may use a different basis of value from the one the accounting framework requires. If the client's expert was asked the wrong question, a perfect answer to it does not help.
In Achekam, ask the client for the expert's report and their terms of engagement through the RFI console, where staff create, send and track requests for documents, answers and confirmations. A request raised from the work item is tracked in the same console as every other request to that client.
Evaluating the findings
Then evaluate the work itself. ISA 620 lists three areas:
- Findings and conclusions: are they relevant, reasonable and consistent with other evidence, such as recent sales in the area or the client's own budgets?
- Assumptions and methods: where significant, are they reasonable in the circumstances? A discount rate or a yield is often the single most sensitive input.
- Source data: where significant, is it relevant, complete and accurate? A valuer who used last year's rent roll has valued a different building.
A worked example in words: the client's valuer values an office block on a yield basis. The audit team confirms the rental income used to the lease schedule it has already tested, compares the yield with ranges published for similar buildings, and asks the valuer, through the client, why the vacancy assumption is lower than the current vacancy. The valuer's answer cites a signed lease starting after year end. The team obtains the lease, concludes the assumption is supported, and records each step.
When the team disagrees with the expert and cannot resolve it, or the engagement partner wants a second view, record the matter as a technical consultation. Achekam lets staff take a consultation on an engagement from question to conclusion and closure, and record a difference of opinion with each party's position, the escalation and the resolution. Estimates more broadly are covered in auditing accounting estimates.
Recording the expert on the audit
Achekam has a Specialists & Experts screen where specialists can be recorded on an audit, and that is the place to name the expert, their field and the area they covered. Two related screens, Audit Resource Pools and Delivery Centres, stay empty because nothing yet adds a pool or a centre, so do not plan to manage a pool of firm specialists there.
The evaluation itself belongs in the procedures on the work item. Each work item lists the procedures to perform and the documents required, and a step is marked done only with a written response and its documents, or set aside with a reason. A sensible set of steps for an area relying on an expert is: assess competence, capability and objectivity; obtain and read the terms; evaluate findings, assumptions and source data; conclude on adequacy.
File the expert's report, their engagement terms and the registration evidence in the client's folder in the Document Centre, which keeps versions and lets staff tag, archive and restore with a reason. A revised valuation then sits beside the draft it replaced, and the reviewer can see what changed. Evidence that arrives from the client in this way is discussed further in client uploads as audit evidence.
Where to start
List every area on your current audits where a figure comes from an expert's report. For each, check whether the file shows the three-part evaluation and the terms of the expert's work, and not just the report. The gaps you find are the procedures to add to your working-paper templates before the next year-end season.
General guidance only, not advice on your own circumstances. Tax and payroll rules change: check the current position with the authority or your adviser.
