Field notes
How Materiality Thresholds Shape What Auditors Sample
Materiality is the threshold that tells an auditor which misstatements would change a user’s reading of the financial statements. In Japanese statutory audits for mid-size manufacturers, that number often starts from a percentage of profit before tax or revenue—then is adjusted for lender covenants and prior-year findings.
Once materiality is set, performance materiality sits lower so that the sum of undetected errors stays within the overall threshold. That is why sample sizes on receivables confirmations or inventory counts can look larger than a controller expects from “just checking a few invoices.”
When profit is thin or volatile, teams may lean more on revenue or total assets. Tell your auditors early if a one-off gain will distort the base; otherwise planning samples may be set against a figure that disappears after adjusting entries.
Practical tip: ask for the planning materiality figure in the kick-off meeting. It will not reveal every test, but it explains why certain cycles receive more days on site.