Refund Fraud
Refund fraud is when someone obtains a refund they aren't legitimately entitled to — for example, by falsely claiming non-delivery, returning a different or damaged item than what was purchased, or exploiting a merchant's refund process directly.
Example
A customer claims a package never arrived despite delivery confirmation, or returns an empty box while claiming a refund for the full contents.
Why it matters
Refund fraud directly erodes margin, and generous, low-friction refund policies — while good for genuine customer experience — can be disproportionately exploited by repeat abusers if not monitored.
How it's detected
Behavioral patterns — a customer with an unusually high refund rate relative to typical customers, or claims that don't align with delivery and tracking data — help distinguish abuse from genuine refund requests.
Return Fraud
Return fraud involves exploiting a retailer's return policy — such as returning stolen or used merchandise for a refund, or returning a different (often lower-value) item than what was originally purchased.
Example
A person purchases an item, uses it, then returns it claiming it was defective or unwanted, exploiting a liberal return window.
Why it matters
Retailers with generous, customer-friendly return policies are more attractive targets for this fraud type, creating a direct tension between customer experience goals and fraud exposure.
How it's detected
Tracking return frequency and patterns per customer, and flagging accounts with disproportionately high return rates relative to purchase volume, helps identify abuse without penalizing occasional genuine returns.
Risk Appetite
Risk appetite is the level of fraud risk a business is willing to accept in exchange for growth, revenue, or customer experience goals — an explicit or implicit tradeoff, since eliminating fraud risk entirely would also eliminate most legitimate business.
Example
A business might explicitly decide it's willing to accept a certain fraud loss rate if it corresponds to a meaningfully higher approval rate and lower onboarding friction for legitimate customers.
Why it matters
Risk thresholds and model tuning decisions should be grounded in an explicit risk appetite rather than defaulting to maximum conservatism, since overly conservative settings suppress legitimate growth without necessarily being a deliberate business choice.
How it's set
Risk appetite is typically set by weighing historical fraud loss data, false decline cost, and broader business growth priorities — and should be revisited periodically as those factors change.
Risk Score
A risk score is a numeric output — often inversely related to a trust score — indicating the likelihood that an identity, transaction, or account is fraudulent or otherwise poses risk, generated by a risk model based on available signals.
Example
A transaction with a mismatched billing address, a new device, and an unusually large purchase amount for that customer might receive an elevated risk score, prompting additional review.
Why it matters
Risk scores let a business set a single consistent policy (thresholds for approve/review/decline) across large transaction volumes rather than making ad hoc individual judgment calls.
How it's calibrated
Thresholds should be set and periodically re-validated against actual outcome data — confirmed fraud and confirmed legitimate cases — since a model's score distribution can drift as fraud patterns and customer behavior change over time.
Risk Signal
A risk signal is any single data point — a device ID, an email's age, a behavioral pattern, a velocity metric — used as an input into a broader risk assessment, distinct from a score or decision, which is an output derived from combining many signals.
Example
"Email created 3 days ago" is a risk signal; it isn't itself a decision, but it's one input a risk model weighs alongside other signals to reach a score.
Why it matters
No single signal is reliably decisive on its own — a new email alone doesn't mean fraud, since many genuine customers also have new emails — which is why robust risk decisioning combines many signals rather than relying on any one.
How it's used
Signals are typically weighted and combined within a model rather than evaluated with simple pass/fail rules, allowing the system to account for context (a new email plus a new device plus an unusual purchase pattern is more meaningful than any signal alone).