Round-sum payments and what they actually signal

£5,000 and £10,000 lines attract attention because they look intentional. Many legitimate retainers, rent charges, and milestone fees are also round. Treating every round sum as an alert floods investigators with noise.

Pair the round-sum filter with vendor age, bank-detail change within ninety days, and weekend posting. That combination is far more informative than amount shape alone. Add a related-party screen if you maintain a known-associates list.

Record false positives. If your facilities team pays round quarterly rent, exclude that vendor from the next scan cycle with a dated rationale. Forensic programmes improve when noise is retired deliberately, not when rules multiply forever.

Share the refined rule set with internal audit so financial auditing work and forensic transaction reviews stay aligned rather than competing for the same exceptions.