Group Audit Reliance and Component Materiality in a Rwandan Bank Group
You are the group engagement partner for Umutekano Bank Group, a Rwandan-listed entity with subsidiaries in Kenya and Uganda. Group materiality is RWF 900 million; performance materiality is RWF 630 million. The Kenyan subsidiary represents 35% of group total assets and 40% of profit before tax, and is audited by a local firm, KLA Associates, whose work you plan to rely on. KLA has set component materiality at RWF 500 million. During review of KLA's file you note: (1) KLA did not test the ECL model on the loan book, which is the subsidiary's largest balance; (2) KLA's audit was completed two weeks before the group reporting deadline but the subsequent-events review stopped at the subsidiary's year-end; (3) KLA is not subject to independent inspection in its jurisdiction. The group audit committee asks whether you can sign the group opinion.
1. Evaluate whether KLA Associates' work provides sufficient appropriate audit evidence for the group audit, applying ISA 600 (Revised).
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ISA 600 (Revised) - group auditor responsibilities:
The group engagement partner retains sole responsibility for the group opinion and cannot delegate it. Reliance on a component auditor requires an evaluation of the component auditor's competence, capabilities, and objectivity, plus direction, supervision, and review of their work.
Issue 1 - Untested ECL model: The loan book is the subsidiary's largest balance and is significant. KLA has not tested the most judgemental estimate. This is a significant risk area and the group auditor must obtain evidence. Options: (a) instruct KLA to perform the work, (b) perform the work ourselves, or (c) engage another firm. Simply accepting KLA's file is not sufficient.
Issue 2 - Subsequent events cut-off: KLA's review stopped at the subsidiary year-end, missing the period up to the group audit report date. The group auditor must perform or request subsequent-events procedures covering the gap, especially given the bank's exposure to credit conditions.
Issue 3 - No independent inspection: Absence of a regulator does not by itself disqualify KLA, but it raises the bar for the group auditor's own evaluation of quality control. We should inspect KLA's quality control policies, review working papers, and consider whether the firm has relevant banking experience.
Component materiality: KLA's RWF 500m is below group performance materiality of RWF 630m, which is acceptable in principle, but the allocation must reflect the component's risk and size (35% of assets). The group auditor should confirm the basis of allocation.
Conclusion: As it stands, the evidence is not sufficient. The group auditor cannot sign without additional procedures on the ECL model and subsequent events, and without a documented evaluation of KLA's quality control. If KLA cannot or will not perform the work, the group auditor must do it directly or modify the opinion.
2. Draft the key instructions you would issue to KLA Associates and explain the documentation you would require before signing.
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Instructions to KLA Associates:
- Scope extension: Perform audit procedures on the ECL model, including challenge of key assumptions (PD, LGD, macroeconomic overlays), reperformance of a sample of calculations, and assessment of data completeness. Report findings and any misstatements.
- Subsequent events: Extend the review to the group audit report date; identify and evaluate events affecting the subsidiary's financial statements and the group's disclosures.
- Communication: Report all misstatements above RWF 45m (5% of component materiality) and any identified fraud, non-compliance, or control deficiencies.
- Independence and quality: Confirm independence, provide the firm's quality control review evidence, and confirm the engagement partner's banking experience.
- Documentation: Provide the completed component audit questionnaire, significant findings memorandum, and management representation letter.
Documentation the group auditor must hold:
- Evaluation of KLA's competence, objectivity, and independence.
- The instructions issued and KLA's response.
- Review notes on KLA's working papers, including the ECL work.
- The group audit team's own procedures on subsequent events and consolidation.
- A conclusion on whether sufficient appropriate evidence has been obtained, and the basis for the group opinion.
Judgement: If KLA fails to deliver adequate evidence, the group auditor should perform the work directly or engage another firm. Signing without resolution would breach ISA 600 and expose the firm to regulatory sanction.