Fraud & AML
Defensible Fraud & APP-Scam Rules in Banking and Payments
Fast, high-volume fraud and scam decisions that now have to be evidenced to a regulator or the Ombudsman after the fact.
Illustrative engagement
The engagement
Where the decision had to hold under scrutiny
Fraud and scam rules operated across banking and payment environments, where decisions had to be made quickly and at scale. With mandatory APP-fraud reimbursement, the question was no longer only whether a rule blocked the right payments, but whether each rule’s logic, thresholds, and rationale could be evidenced to a regulator or the Financial Ombudsman after the fact. Illustrative work focuses on documenting why each rule exists, recording its calibration, and making decision outcomes traceable. This turns a rule set into one that can be defended on the record rather than merely explained after the fact.
Key challenges
The problem, and what was done about it
Challenge 01
APP-scam reimbursement made every payment-block decision reviewable after the fact, but the rule set had grown into hundreds of overlapping thresholds no one could fully explain. A blocked genuine payment — or a missed scam — could not be justified on the record when the Ombudsman asked.
What was done
Rebuilt the rules around documented rationale: each rule tied to the risk it targets, thresholds calibrated against measured false-positive and false-negative impact, and every firing logged with its reason and inputs — so any single decision could be reconstructed and defended months later.
Challenge 02
Aggressive rules were blocking legitimate payments, harming genuine customers and generating complaints the firm could not justify — while loosening them risked letting real scams through.
What was done
Recalibrated thresholds against measured customer-impact and documented the trade-off behind each rule, so a blocked payment could be explained and the balance between protection and friction was defensible rather than arbitrary.
Illustrative — reconstructed from the engagement context
How Verdica makes it defensible
The same five stages, applied to this decision
Every engagement runs the same path. For this one, the weight falls on Trace, Certify, Evidence — the stages where a decision of this kind is most often challenged.
Trace
Map every point where the decision could be challenged — before a line of logic is written.
Reason
Build the logic in the open: explainable, deterministic, same input, same output — no black box.
Assure
Validate coverage and oversight before anything ships; nothing unassessed is waved through as safe.
Certify
Lock an immutable, versioned record of exactly what was decided and on what basis.
Evidence
Hand over the audit trail — the pack that holds the moment someone says prove it.
Related engagements
The same standard, holding elsewhere
Discuss a related situation
A decision like this can be made defensible — on the record, not after the fact
A short discussion is usually enough to locate where the risk sits — in the logic, the controls, the evidence, or a combination — and where Verdica makes it hold.