Marketplace Fraud Prevention

Fraud Prevention Built for Both Sides of Your Marketplace

Marketplaces run on trust. Unlike most fraud tools, which were built for a single checkout flow, SEON screens both buyers and sellers in real time, catching fake accounts, stolen cards, and chargebacks so you can approve good users faster and scale with confidence.

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Approve More Buyers, Grow Your Marketplace Faster

2,000+

registrations screened daily with zero friction for legitimate users

33

countries scaled to tens of thousands of transactions without adding fraud headcount

Protect the Entire Path to Purchase

Fraud starts before checkout. It should stop there. With SEON, marketplaces can guard across every stage of the customer journey, minimizing losses and maximizing customer and buyer satisfaction.

Seller Onboarding & Verification

Screen buyers and sellers at signup with digital footprint analysis to approve good users fast and block fake accounts before they enter.

Customer Account Security

Fortify customer accounts by detecting suspicious devices and login activity with device intelligence.

Transaction

Score every transaction in real time to stop stolen cards and payment fraud without slowing down legitimate buyers.

Returns & Refunds

Flag return and refund abuse before it hits margins, using behavioral and transaction history.

Chargeback Investigation

Prevent disputes before they start and win the ones that count with rich, exportable transaction evidence such as proof of delivery photo.

Protect Your Marketplace
from Seller Signup to Payout

SELLER ONBOARDING

Approve Real Sellers Fast.
Block Fake Ones at Signup

  • Score every seller at signup using identity verification, device intelligence, network detection, and digital presence
  • Clear low-risk sellers automatically and approve more customers without manual review
  • Surface synthetic identities and stolen business credentials before the first listing goes live
  • Monitor past approval and onboarding, where most platforms stop looking
How marketplaces screen sellers at scale

PAYMENTS AND PAYOUTS

One View Across Buyer Checkout and Seller Payout

  • Catch card testing where it actually happens — through seller-initiated flows, not buyer checkout
  • Link buyer and seller accounts by shared devices, IPs and behavior to surface fraud rings 
  • Flag payout risk before funds leave the platform, not after the chargeback lands
  • Hold acceptance rates while blocking the transactions that create chargeback liability
Payment fraud on two-sided marketplaces

BUYER ACCOUNTS AND PLATFORM ABUSE

Protect Your Buyers and the Community Around Them

  • Stop account takeovers before a fraudster initiates a transfer from a compromised buyer’s account
  • Detect multi-accounting by matching devices, emails and behavior across the platform
  • Shut down promo and referral abuse without penalizing legitimate first-time buyers
  • Surface coordinated review and reputation manipulation before seller trust is damaged

RULES, TRUST AND SAFETY OPERATIONS

Risk Logic Your Team Controls

  • Write and edit logic directly to shut down emerging seller and buyer fraud fast, with no engineering ticket required
  • Validate onboarding and transaction logic against real historical data, powered by SEON’s deep digital footprint and device signals
  • Implement changes immediately when a fraud ring attacks or a new abuse pattern appears
  • Automate the routine onboarding and transaction decisions that make up most of the caseload, freeing analysts to focus on the high-risk buyers and sellers where judgment matters
How to choose a fraud detection tool for your marketplace

HOW MARKETPLACE FRAUD PREVENTION WORKS

From Raw Signal to
Risk Decision in Milliseconds

Every buyer and seller runs through the same four steps, from the first data signal to an approve, review or block decision.

1.

Collect Signals

SEON builds a digital footprint from an email or phone you already collect, enriched with device, IP and behavioral signals. No extra fields, no added friction.

2.

Score Risk in Real Time

Every signal is weighed against your rules at signup, checkout and payout. Buyer and seller flows run separate logic, scoring risk in milliseconds.

3.

Automate Alert Triage

Low risk is auto-approved, clear fraud is blocked, and only the uncertain middle goes to review. Growth never waits on manual checks.

4.

Investigate & Take Action

Shared emails, devices, IPs and payout details link accounts to expose whole rings. Post-approval monitoring catches shifts a one-time check would miss.

Discover How Companies Win

“The simplicity of the product, the simplicity of the machine learning rules engine, plus the support and working with a dedicated fraud specialist – it all made a tremendous difference.”

Jonas Jaeger

Co-Founder, a marketplace operating across 33 countries

Read story

“We wanted a way to proactively stop fake sign-ups without adding friction for real users.”

Olivier Novel

Fraud Analyst, Europe’s largest collectible card game marketplace

Read story
See all customer stories

Learn More About Preventing Marketplace Fraud

FAQ

What type of marketplace fraud does SEON prevent?

SEON prevents payment fraud, card testing, account takeover, promo and coupon abuse, return fraud, refund abuse, chargeback fraud and multi-accounting. The platform detects threats at every stage of the customer journey from registration through post-purchase disputes using a combination of device intelligence, behavioral analytics and AI-driven scoring

How is fraud prevention on a two-sided marketplace different from traditional eCommerce?

A traditional fraud solution protects one flow: the buyer at checkout. A marketplace has to build trust on both sides, evaluating seller onboarding, payout abuse, multi-accounting and cross-account rings that checkout tools never see. SEON covers the full journey on both sides with real-time digital footprint, device intelligence and flexible risk rules.

How does SEON prevent seller onboarding fraud?

Much of the risk appears before the seller’s sign up. SEON scores seller risk in real time using email age, device fingerprinting and behavioral signals, then keeps watching the high-risk window between sign-up and first sale, without adding friction for legitimate sellers.

How does SEON stop card testing and payout fraud through seller accounts?

Card testing often runs through the seller payment flow, where stolen cards clear as ordinary seller activity and slip past buyer velocity rules. SEON watches both sides, flagging device consistency, email quality and payout timing before payouts settle, closing the seller-side gap while keeping acceptance rates high.

Take the First Step Toward Transformative Fraud Prevention

“Trust and safety are core fundamentals on which we’ve built our entire platform. Without a solution like SEON, we wouldn’t have been able to scale the way we did or satisfy our users to the degree needed to enable our growth.”

Jonas, Co-Founder, buycycle

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