Method
Sampling digital wallet populations without theater
Random samples look rigorous until a single high-value wallet transfer sits outside the draw and nobody planned for it. Digital wallet compliance audits for fintech need strata that match risk, not spreadsheet defaults.
Define the unit
Is your unit a wallet, a transaction, a customer day, or a settlement batch? Mixing units mid-test is how teams lose arguments with second line. Write the unit on the first line of the sampling plan.
Strata that earn their keep
Useful strata often include new wallets in the first 30 days, wallets with freezes in the period, nested merchant wallets, and transfers above a named threshold. If a stratum has five items, test all five. Pretending they are “covered” by a broad random draw is theater.
Document why you stopped
State the stop rule before testing. Expanding the sample midstream because a finding appeared may be right—but only if you record the decision and avoid quietly discarding clean early items.
We drill these habits in Wallet Ledger Audit Studio with messy extracts on purpose. Clean teaching data hides the judgment calls that matter.