Fraud is rare, constantly changing and must be caught in milliseconds without blocking genuine customers.
An ensemble machine-learning model that scores each transaction for fraud risk and raises alerts.
Extra Trees ensemble, data-balancing techniques, feature engineering, risk scoring.
Earlier fraud detection with fewer unnecessary blocks on genuine transactions.
Digital payments have grown rapidly through cards, PayNow, digital wallets and online banking. Every increase in transaction volume creates new opportunities for fraudsters, and every fraudulent transaction means financial loss, operational effort and damaged customer trust.
TokenWave AI developed a machine-learning fraud detection system that evaluates each transaction, assigns a fraud probability and raises alerts for high-risk activity. The system is specifically designed to handle the extreme imbalance of real-world financial data, where genuine transactions vastly outnumber fraudulent ones.
Financial institutions and payment businesses have traditionally relied on fixed rules - for example, flagging transactions above a certain amount or from unusual locations. These rules are easy to understand but quickly become outdated as fraud patterns evolve.
At the same time, overly strict rules block legitimate customers, leading to frustration, abandoned purchases and support costs. The challenge is to be both highly sensitive to fraud and precise enough to leave genuine customers undisturbed.
Fraud represents a tiny fraction of all transactions, which makes it hard for standard models to learn.
Fixed rules miss new fraud patterns and require constant manual updates.
Blocking genuine transactions damages customer experience and revenue.
Risk must be assessed within the short time window of a payment authorisation.
We followed a structured, problem-first process - understanding the real-world problem before choosing the technology, and validating every stage before moving to the next.
We analysed how fraudulent transactions differ from genuine ones and what a practical fraud alert must deliver - speed, accuracy and a clear risk score.
Transaction data was cleaned and prepared, and data-balancing techniques were applied so the model could learn effectively from the small number of fraud examples.
Meaningful features describing transaction behaviour were prepared so the model could distinguish unusual activity from normal patterns.
Multiple machine-learning approaches were evaluated, with an Extra Trees ensemble selected for its strong performance and robustness, based on research into credit-card fraud detection.
The model outputs a fraud probability for each transaction, with configurable thresholds for alerts, holds or additional verification.
A machine-learning system that scores every transaction for fraud risk and raises alerts in real time - even when fraud cases are extremely rare in the data.
Transaction is received
Features are prepared
Model evaluates the transaction
Fraud probability is calculated
Risk threshold is applied
Alert or approval is issued
Every transaction receives a fraud probability score.
Data-balancing techniques ensure rare fraud cases are learned effectively.
Extra Trees combines many decision trees for robust, stable predictions.
Businesses can tune sensitivity based on their risk appetite.
Better precision means fewer genuine customers are disturbed.
The model can be retrained as new fraud behaviour emerges.
Suspicious transactions are identified before losses grow.
Fewer genuine transactions are blocked unnecessarily.
Risk teams spend time on the cases that truly matter.
“Good fraud detection is invisible to honest customers. The system should stop the fraudster while letting everyone else pay without friction.”
— TokenWave AI Project Team
This case study describes an in-house research and development project by TokenWave AI. Outcomes are described qualitatively; actual performance depends on the data, environment and scale of each deployment. Want to apply this solution to your business? Book a free consultation.
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