4.11 Matching Methods to Situations: Strengths, Weaknesses & Judging Sufficiency
Key Takeaways
- ICAB Syllabus 2023 outcomes 3(c), 3(d), 3(f) and 3(g) require candidates to recognise the strengths and weaknesses of each evidence method, identify when each should and should not be used, select methods for a scenario, and recognise when evidence is sufficient and appropriate.
- Each of the seven procedures has a specific weakness: observation is valid only at the moment it occurs, inquiry alone is never sufficient, and inspection proves a document exists rather than that a transaction was genuine.
- Sufficiency and appropriateness interact: higher-quality evidence reduces the quantity needed, but more low-quality evidence never compensates for poor quality.
- Cost and inconvenience are never a valid basis for omitting a necessary procedure where no acceptable alternative exists.
- Where evidence cannot be obtained, the matter becomes a scope limitation, which is escalated to a senior colleague and may lead to a qualified opinion or a disclaimer depending on materiality and pervasiveness.
Matching Methods to Situations: Strengths, Weaknesses & Judging Sufficiency
Four related learning outcomes are examined together in scenario questions: recognising the strengths and weaknesses of each method of obtaining evidence, identifying the situations in which each should and should not be used, selecting appropriate methods for a given business scenario, and recognising when the quantity and quality of evidence gathered is sufficient and appropriate to draw reasonable conclusions.
1. Strengths and weaknesses of each method
| Method | Strength | Weakness | Should NOT be relied on alone for |
|---|---|---|---|
| Inspection of records and documents | Documentary, often reviewable and reperformable; external documents rank high | Proves the document exists, not that the underlying transaction was genuine; documents can be forged or altered | Occurrence, where the document is internally generated |
| Inspection of tangible assets | Direct auditor knowledge; strong for existence | Says nothing about ownership, condition of title, or valuation | Rights and obligations; valuation |
| Observation | Direct auditor knowledge of how a process is actually performed | Valid only at the moment of observation; behaviour changes when watched | Operating effectiveness across a whole period |
| External confirmation | External, direct and documentary — the top of the hierarchy | Non-responses; the confirming party may sign without checking; slow | Completeness of liabilities, where the auditor does not know whom to ask |
| Recalculation | Conclusive on arithmetic; cheap; reperformable | Only tests arithmetic, never the validity of the inputs | Any assertion depending on the underlying data |
| Reperformance | Strong evidence a control actually works, obtained directly by the auditor | Time-consuming; needs the same data the client used | Nothing much, but it is expensive |
| Analytical procedures | Efficient; covers a whole population; identifies unexpected relationships | Depends on the predictability of the relationship and the reliability of the data used to build the expectation | Areas that are volatile or judgemental |
| Inquiry | Fast; the only way to obtain explanations and to understand intent | Internal, oral and from an interested party | Anything, on its own — inquiry alone never provides sufficient appropriate evidence |
The line to memorise: inquiry alone does not provide sufficient appropriate audit evidence. It must be corroborated.
2. When a method should not be used
Scenario questions often turn on selecting the wrong procedure for the assertion. The recurring mismatches:
| Objective | Wrong choice and why | Right choice |
|---|---|---|
| Test completeness of revenue | Vouching from the sales ledger back to dispatch notes — it can never find a sale that was never recorded | Trace forward from pre-numbered dispatch notes |
| Test completeness of payables | Circularising the recorded payables listing — the missing supplier is not on it | Search for unrecorded liabilities; supplier statement reconciliations |
| Test ownership of inventory | Physical inspection at the warehouse — goods on consignment look identical | Inspect consignment and sale-or-return agreements; confirm with third parties |
| Test operating effectiveness of a control across a year | Observing the control once | Inspect evidence of the control across a sample spanning the whole period, or reperform it |
| Test valuation of inventory | Counting the quantity | Compare cost with after-date selling prices |
| Confirm a bank balance | Asking the finance manager | Direct confirmation from the bank |
3. Judging sufficiency and appropriateness
Sufficiency is quantity; appropriateness is quality, comprising relevance and reliability. They interact but do not substitute for one another.
- As assessed risk rises, more evidence is needed.
- As the quality of evidence rises, less may be needed.
- More poor evidence never cures poor quality. Fifty internally generated spreadsheets do not equal one bank confirmation.
Factors driving the quantity required:
- Assessed risk of material misstatement at the assertion level.
- Materiality of the item.
- Results of procedures already performed, including whether misstatements were found.
- The quality of the evidence obtained.
- The homogeneity of the population — variable populations need larger samples.
- Experience from prior periods.
The cost rule
Difficulty, time and cost are not, in themselves, a valid basis for omitting a procedure for which there is no alternative. Cost may legitimately influence the choice between two procedures that both provide appropriate evidence; it may not justify obtaining no evidence at all. This appears regularly as a scenario in which a client says the confirmation exercise is "too disruptive".
Corroboration and contradiction
Evidence from different sources that points the same way is more persuasive than any single item. Conversely, where evidence from one source is inconsistent with evidence from another, the auditor must investigate and modify the procedures as necessary — the inconsistency itself is a finding, not an inconvenience to be smoothed over.
4. When evidence cannot be obtained: escalation
Learning outcome 3(i) requires candidates to recognise issues arising while gathering evidence that should be referred to a senior colleague. Escalate whenever you encounter:
- A scope limitation — records destroyed, management refusing access, a confirmation blocked by the client.
- Suspected fraud or a deliberate irregularity, however small the amount.
- Suspected non-compliance with laws and regulations.
- Evidence contradicting management's explanation, or explanations that keep changing.
- A matter beyond your competence or experience — a complex valuation, an unfamiliar financial instrument, a specialist tax question.
- Pressure from the client to reduce testing, accept an unsupported explanation or alter a conclusion.
- A material misstatement that management declines to adjust.
The correct behaviour is to document what you found, stop, and refer upward — not to resolve a matter beyond your authority, and not to accept a client explanation because a partner is unavailable. An unresolved scope limitation flows through to the opinion: qualified if material but not pervasive, disclaimer if material and pervasive.
5. A structured answer template
For a scenario asking you to select procedures:
- Identify the assertion at risk — not the account, the assertion.
- Choose the direction of testing implied by that assertion.
- Name the specific document or third party the evidence comes from, in the entity's own language — goods dispatch note, Mushak-6.3, supplier statement, title deed.
- State what the procedure proves and, where relevant, what it does not.
- Identify anything that must be escalated.
Answers that name a document and an assertion earn marks; answers that say "check the records" do not.
A client tells the audit team that circularising trade receivables is too disruptive and offers instead to provide its own schedule of balances. How should the auditor respond?
Which statement correctly describes the relationship between the sufficiency and the appropriateness of audit evidence?
An audit junior finds that supporting documentation for a material payment has been destroyed and that the finance manager's explanation changes each time it is discussed. What is the appropriate course of action?