The Outlier Lab

Retail and Ecommerce

Merchant-side transaction fraud across CNP checkout, refunds and returns, promo abuse, BOPIS and gift cards, and how card network rules and return economics shape retail defenses.

Business model and fraud surface

A retailer is the merchant of record. For card-not-present sales that means it carries fraud liability unless authentication (3-D Secure, network tokens with qualifying data) shifts it to the issuer. It also carries chargeback fees and network monitoring-program exposure, plus the full cost of its own refund, return, promotion and gift card policies. Unlike banks, retailers have few regulatory floors, so most of their fraud exposure comes from policies they wrote themselves.

Diagram: Customer, Checkout risk decision, Issuer, Fulfillment: ship, BOPIS, curbside, Returns and claims

Where value leaves, and how quickly it becomes unrecoverable:

Value leavingExposure windowMechanism
Shipped goods on a stolen cardUntil the fraud chargeback, often 30–90+ daysCard-Not-Present Fraud
Goods handed over at BOPIS/curbsideSeconds. Pickup identity is the only controlCard-Not-Present Fraud, Account Takeover (ATO)
Refund issued before the return is inspectedInstant-refund policies refund at drop-off or first carrier scanRefund and Return Fraud
Refund on an INR claimImmediate appeasementBuyer Protection Claim Abuse (INR and SNAD)
Gift card or store-credit balanceDrained in minutes and resoldGift Card Fraud
Promo and loyalty valueInstant at checkoutPromo Code Abuse, Loyalty and Rewards Redemption Fraud
Legitimate purchase later disputedChargeback windowChargeback and Friendly Fraud

The numbers. The MRC's 2026 survey of 1,278 merchants put payment fraud at 3.2% of global ecommerce revenue. 62% of merchants reported more first-party misuse disputes and 57% more refund/policy abuse. Refund/policy abuse has been merchants' most common attack in the MRC survey since 2024. On returns, Appriss Retail estimated $706B of merchandise returned in the US in 2025, and about $100B (14.2%) of it preventable fraud and abuse. The NRF and Happy Returns projected $850B in returns for 2025 (15.8% of sales; 19.3% online) and estimated 9% of returns are fraudulent. Methods differ, so read these figures as a range of estimates.

Decision points: account creation, login, checkout scoring and 3DS routing, payment method add, promo application, fulfillment release (especially BOPIS handover), return authorization and refund timing, claim adjudication, gift card activation and redemption, loyalty redemption, and representment.

What fraudsters want here

ActorWantsConceptual path
Stolen-card resellersGoods to resellValidated card → high-resale basket → reship or pickup → resale
Card testersValidated card dataLow-value authorizations at weak checkouts (Card Testing)
First-party abusersFree goodsBuy → dispute or claim → keep the goods; wardrobing; empty-box returns
Refund-as-a-service operatorsFees for faking refundsScripted claims, support social engineering, sometimes insiders
Promo farmersStacked discounts and creditsMany accounts × new-customer offers
Gift card fraudstersLiquid stored valueStolen-card purchases of cards, balance draining, scam-sourced cards (Gift Card Fraud)
Account takeover crewsSaved cards, points, store creditStuffing or phishing → purchase or redeem → ship or pick up
InsidersCollusion payoutsFake returns, discount overrides, loyalty credits (Insider Fraud)

Fraud across the customer lifecycle

StageMechanismsKey controls
OnboardingFake Account Creation (Bots), Multi-Accounting for new-customer promosBot Management and CAPTCHA, Email Risk Signals, Device Reputation and Linkage
LoginCredential Stuffing, Account Takeover (ATO) for saved cards and balancesBreached Password Detection, Rate Limiting and Throttling, Risk-Based Authentication and Step-Up, Passkeys and Phishing-Resistant Authentication
Account maintenanceShipping-address and email changes after ATO, saved-card addsContact Change Cooling-Off Periods, Account Change Events scoring
Transaction (checkout)Card-Not-Present Fraud, Card Testing, Promo Code Abuse, Business Logic Exploitation, Triangulation Fraud (as the victim merchant)Real-Time Transaction Risk Scoring, 3-D Secure and Card Verification, Promotion Design Guardrails, Velocity and Exposure Limits
Fulfillment (BOPIS, curbside, ship)Pickup by an unauthorized person, reshipping, address manipulationPickup verification, Address Risk Signals, hold-for-review on risky BOPIS orders
RewardsLoyalty and Rewards Redemption Fraud, Referral Abuse, Sign-Up Bonus AbuseReward Vesting and Clawback, Referral Program Controls
Dispute and returnsRefund and Return Fraud, Chargeback and Friendly Fraud, Buyer Protection Claim Abuse (INR and SNAD)Claims and Returns Policy Controls, Dispute and Return History scoring, representment with compelling evidence
Payout (stored value)Gift Card Fraud (draining, scam-sourced cards), store credit resaleGift card velocity limits, activation controls, Negative Lists and Deny Lists
Customer supportRefund-as-a-service social engineering, appeasement abuse, Insider FraudCustomer Support Verification Protocols, Insider Access Controls, Support Team Fraud Training

Top mechanisms, ranked

  1. Refund and Return Fraud: wardrobing, empty boxes, item swaps, stolen-merchandise returns, counterfeit receipts and refund-as-a-service. In Appriss Retail's 2024 survey, 60% of retailers cited wardrobing, 55% returns with fraudulent or stolen tender, and 48% stolen-merchandise returns. NRF-reported increases centered on overstated return quantities, empty boxes and decoy returns. BORIS returns are the fastest-growing fraud and abuse vector (Appriss, 2025).
  2. Chargeback and Friendly Fraud: cardholders disputing legitimate purchases. The MRC says first-party misuse is up to 80% of fraud-related chargebacks for many members. Visa's Compelling Evidence 3.0 (2023) and Mastercard's First-Party Trust (2024 US rollout) give merchants data-driven defenses.
  3. Card-Not-Present Fraud: stolen and phished card data buying resalable goods. Phishing-fed, freshly provisioned wallet tokens shorten the time from compromise to fraud.
  4. Promo Code Abuse: leaked and stacked codes, new-customer offers farmed through Multi-Accounting, and code enumeration. Ravelin's survey found 53% of merchants saw more promo abuse.
  5. Card Testing: enumeration and account testing at weak checkouts and donation-style pages. Visa's VAMP now tracks enumeration (a 20% ratio with 300,000+ attempts) alongside fraud and dispute ratios.
  6. Gift Card Fraud: stolen cards buying gift cards, balance draining, and gift cards as the payment method in scams. Scammers name specific retail brands, so retailers see the purchase at their registers. The FTC found gift cards were the most-reported fraud payment method from 2018 through 2021, and about one in four people who lost money paid with them.
  7. Account Takeover (ATO): monetizing saved cards, loyalty points and store credit, often with BOPIS to avoid address checks.
  8. Buyer Protection Claim Abuse (INR and SNAD): "never arrived" and "damaged" claims. Appriss estimated about $21B in claims and appeasement fraud and abuse in 2024.
  9. Loyalty and Rewards Redemption Fraud: points theft via ATO, insider manipulation, logic-flaw redemptions.
  10. Business Logic Exploitation: price errors, stacking bugs, race conditions in gift card and promo redemption. Rare, but they can run up large losses within hours.

Also relevant: Triangulation Fraud (the retailer is often the unknowing merchant whose goods are bought with stolen cards to fulfill marketplace orders), Insider Fraud (39% of executives cited employee return fraud or collusion), and Agentic Commerce Fraud (63% of MRC 2026 merchants are exploring agentic payments, and agent authorization and liability are unsettled).

Regulatory environment

Retail fraud is governed more by network rules and contracts than by statute:

AreaWhat appliesWhy the fraud team cares
Card network rulesVisa VAMP (from April 2025) counts fraud reports plus disputes against settled CNP transactions. Enforcement began October 2025, and the merchant "excessive" threshold dropped to 1.5% in most regions on April 1, 2026. Mastercard runs parallel programsRatios drive fees, acquirer pressure and potentially loss of acceptance. Every fraud report counts, even ones you refund. See Card Network Dispute Rules
Dispute evidenceVisa Compelling Evidence 3.0 for 10.4 fraud disputes (two prior undisputed transactions 120–365 days old, matching device/IP and other data). Mastercard First-Party TrustData retention and linkage determine whether you can win first-party disputes
Authentication3-D Secure liability shift (issuer-dependent). SCA where you sell into the UK/EURouting to 3DS is a liability and conversion decision
PCI DSSCard data security, including payment-page script controls (v4.0)Skimming and checkout tampering prevention
Gift cardsReg E § 1005.20 (federal expiration and fee rules), state unclaimed-property and gift card laws. FTC guidance warning consumers that requests to pay with gift cards are scamsShapes product design and cashier-intervention programs
FTC Act and Mail Order RuleShipping-time representations, refund obligations, honoring advertised return and protection policiesRestrictive return or claim policies must match what you advertise
PrivacyState privacy laws on using return history, device data and identity for decisionsReturns-authorization scoring needs disclosure and data minimization. See Privacy and Data Use in Fraud Prevention
Organized retail crimeState ORC laws and task forcesReturn fraud with stolen goods overlaps ORC investigations

Key metrics

MetricDefinitionNotes
Fraud chargeback rateFraud disputes ÷ CNP transactions (count and $)Report against VAMP and Mastercard thresholds
VAMP ratio(Fraud reports + disputes) ÷ settled CNP transactionsYour acquirer watches this monthly
Order approval rate and false decline rateApproved ÷ attempted; good orders declinedDeclines are a cost. See Friction and Customer Experience Tradeoffs
Manual review rate and review accuracyOrders reviewed ÷ orders; QA-measured accuracySee Alert Review Operations, Fraud QA Program
Representment win rateDisputes won ÷ disputes represented, split by reason codeCE 3.0 eligibility rate is a leading indicator
Return rate and return fraud/abuse rateReturns ÷ sales; fraudulent or abusive returns ÷ returnsSplit by channel (BISRIS, BORIS, BORO)
Claim rate (INR/SNAD) and repeat-claimant shareClaims per 1,000 orders; share from repeat claimantsConcentration exposes abuse quickly
Promo cost per incremental customerPromo spend ÷ customers retained at 90 daysMeasures abuse in marketing's language
Gift card fraud rateFraudulent activations or drained balances ÷ volumePlus scam-intervention saves at the register
Card testing attempts blockedEnumeration attempts stopped at the edgeAlso a VAMP enumeration ratio input

General definitions: Fraud Metrics and KPIs, Loss Taxonomy and Attribution, Fraud Labeling and Feedback Loops (chargeback and return labels mature on different clocks).

How fraud teams are typically organized here

Retail fraud often sits in payments (finance-aligned) or loss prevention (stores and operations), and the split shapes blind spots:

  • Payments/ecommerce fraud: checkout risk, 3DS strategy, chargebacks, card testing and vendor management. Measured on chargeback rate and approval rate.
  • Loss prevention and asset protection: in-store theft, ORC, return fraud at the counter, insider investigations. Measured on shrink.
  • Returns and customer care operations: return policy, appeasements, claims. Often measured on customer satisfaction, with no loss metric.
  • Marketing/loyalty: promotions and loyalty programs, often with no fraud owner at all.
  • Data science: shared or embedded. Returns-abuse models often live with returns ops.

The losses fall between those teams. A BORIS return of a stolen-card online purchase is a payments loss, an LP event and a returns-ops decision at the same time. Mature retailers create an omnichannel fraud function with one entity view across online orders, store transactions, returns, loyalty and gift cards, and a single net-loss number. See Fraud Operating Model, Cross-Functional Partnerships, New Product and Promo Launch Review, Vendor Selection and Evaluation.

Industry-specific signals and controls

Signals

Controls

Members: Playbook - Chargeback Management Members, Playbook - Card Testing Members, Playbook - Refund and Claims Abuse Members, Playbook - Sign-Up Bonus and Promo Abuse Members, Playbook - Account Takeover Members, Playbook - Business Logic Exploit Response Members, Playbook - Scam Intervention Members, Playbook - Insider Fraud Members.

Notable public cases

  • Amazon v. refund-service operator (2025): default judgment totaling over $2.4M: $2M against the operator of a refund-fraud service that recruited warehouse insiders, and the rest against four former employees who approved more than $400K in fake returns. See Case Study - Amazon Refund-as-a-Service Crackdown (2023-2026).
  • Case Study - Talens Counterfeit Coupon Scheme (2020): about $31.8M in counterfeit coupon losses to retailers and manufacturers.
  • Case Study - Pinduoduo Coupon Exploit (2019): a promo logic flaw exploited at scale within hours.
  • FTC gift card data spotlights (2020–2021): gift cards as the leading scam payment method, with named retail brands where victims bought cards. This is the evidence base for register-level intervention programs.
  • FTC and GOAT (2024–2026): redress over refund and buyer-protection promises that were allegedly not honored. The case shows that anti-abuse policy has to match advertised policy.
  • Case Study - DraftKings Credential Stuffing (2022): a stuffing pattern that applies directly to retail accounts with stored value.

Sources and further reading