80%

of Tier 3 audits had significant issues — sampling methodology is the #1 root cause

ISA 530 — Sampling Methodology Inspection Readiness Checklist

12 deficiencies regulators flag most often. Score your sampling approach before they do.

80% of Tier 3 audits fail inspection. Sampling methodology is the #1 root cause. The FRC ran a dedicated thematic review on this in November 2023 and found pervasive failures — even at Tier 1 firms. If Big 4 firms are getting this wrong, what are the chances you are?

What's inside

5-sheet Excel workbook with interactive self-assessment, finding details with regulatory backing, visual 12-step sampling decision map, regulatory stats dashboard, and full source references with hyperlinks.

1. Sample size not linked to assessed risk and tolerable misstatement (ISA 530.7)

The FRC thematic review found firms selecting sample sizes from tables without demonstrating the link between the assessed risk, tolerable misstatement, and the sample size chosen.

2. Haphazard selection presented as random sampling (ISA 530.A13)

PCAOB found 38% of sampling deficiencies involved auditors describing their selection as "random" when the method used was haphazard, introducing selection bias.

3. No projection of misstatements found in sample to population (ISA 530.14)

Auditors identified errors in samples but failed to project the likely misstatement to the entire population, as required by ISA 530.

Plus 9 more findings — including a visual 12-step sampling decision map from population definition to ISA 450 accumulation. All in a free Excel workbook.