Marketplaces

Marketplaces Face Complex Fraud — We’ve Spent a Decade Staying One Step Ahead

Build marketplace trust without slowing down growth.

Marketplaces move at two speeds: real buyers and sellers and fraud rings operating at scale. Accertify helps you approve more good activity while stopping high-risk payments, account abuse, and disputes – so you can grow GMV and protect your platform experience.

Marketplace fraud isn’t one problem. It’s a multi-sided risk system.

In marketplaces, risk doesn’t sit in a single step – it moves across buyers, sellers, listings, payments, and payouts. Fraudsters exploit the complexity: synthetic accounts to unlock incentives, account takeover to drain stored value, triangulation and resale schemes, and “friendly fraud” that becomes expensive disputes. Meanwhile, overly aggressive controls create false declines that hurt conversion and shift demand to competitors.

Accertify helps marketplaces get the trade-off right: high approvals + low loss, with end-to-end protection powered by machine learning, community insights, and expert-led strategy.

Marketplace fraud threats Accertify addresses

Account takeover (ATO) & buyer/seller account abuse

Fraudsters use breached credentials to hijack accounts, change payout details, and make unauthorized purchases – or weaponize accounts for scams. Accertify’s Account Protection monitors logins and account events in real time using device intelligence and user behavior analytics to distinguish authentic users from attackers, without unnecessary friction.

Fake accounts, synthetic identities & onboarding abuse

Bad actors create networks of accounts to farm promotions, launder funds, or seed scams. Accertify helps you identify abnormal account creation patterns and multi-accounting behavior early before they scale.

Promo abuse, referral fraud & incentive gaming

Marketplaces rely on incentives to grow, but abuse drains margin and pollutes acquisition. Accertify detects linked identities, repeated behaviors, and coordinated patterns so you can target controls to abusers while keeping legit users frictionless. 

Checkout fraud, card testing & triangulation patterns

Fraudsters probe checkout flows at high velocity and use stolen credentials to place orders for resale or fulfillment. Accertify’s Fraud Detection uses a multi-layered approach underpinned by machine learning, device intelligence, and behavioral signals to improve detection while preserving conversion.

Seller-side risk: payout fraud & settlement manipulation

Marketplace payouts are a prime target, especially when fraudsters can change bank details, reroute funds, or exploit refund workflows. Accertify helps you assess risk across account events and transactions so you can apply stepped controls to high-risk payout changes and suspicious settlement activity.

Refund, return & policy abuse

Item-not-received claims, false refunds, and policy gaming are increasingly common especially in high-volume categories. Accertify’s Returns & Abuse Protection helps you identify patterns of abusive behavior and take action quickly while preserving the experience for good customers.

Chargebacks & disputes (“friendly fraud”)

Disputes cost revenue and ops time – and they can damage your processor relationships. Accertify’s Chargeback Management streamlines dispute workflows with automation, templates, and reporting, helping teams improve outcomes and scale efficiently.  

Purpose-built for marketplace risk.

Accertify helps marketplaces balance trust, safety, and conversion with a platform designed to deliver the right decision at the moment it matters – across both sides of your network. With end-to-end protection from login to dispute, advanced AI and machine learning, community insights, and expert-led risk strategy, you can scale safely as your marketplace grows.

  • End-to-end protection across the journey from account activity through disputes.
  • Advanced AI + machine learning + community insights to detect emerging patterns faster.
  • Flexibility & control so you can tune decisions to your risk tolerance and marketplace policies.

  • Expert support from teams who understand complex, multi-sided marketplace risk.

Protect every step of the marketplace journey

Whether you’re a product marketplace, services marketplace, or platform with complex payouts, risk shows up in predictable moments. Accertify helps you win those moments without adding unnecessary friction.

  • Account protection for buyer & seller logins
    Stop ATO, credential stuffing, and suspicious account activity.
  • Onboarding defense for new accounts & sellers
    Identify synthetic identities, fake accounts, and multi-accounting early.
  • Listing + intent signals (behavioral risk)
    Detect anomalous behaviors that correlate with scam attempts and abuse patterns.
  • Checkout fraud detection & velocity controls
    Prevent card testing and high-risk transactions while keeping approvals high.
  • Payout-change & settlement risk
    Flag suspicious payout updates and downstream actions tied to loss.
  • Refund/returns/policy abuse detection
    Differentiate good customers from abusers to reduce leakage.
  • Chargeback management & dispute outcomes
    Automate workflows and improve dispute performance at scale.

 

Turn marketplace trust into measurable performance

  • Approve more legitimate buyers and sellers (reduce false declines, protect conversion)
  • Reduce fraud losses, refund leakage, and chargebacks (less margin erosion)
  • Operate faster with fewer manual touches (automation + smarter routing and review)

 

Trust at scale

In 2025, Accertify protected more than 10 billion transactions globally, worth over $1.2 trillion USD, helping clients prevent 30.7 million distinct fraud and abuse attempts worth nearly $5.8 billion in total attempted risk.

Proof from a marketplace leader: Viator

Viator, a global marketplace with 395,000+ tours and activities, partnered with Accertify to strengthen fraud and chargeback performance as their marketplace scaled.

After implementation, Viator achieved:

  • 75% reduction in fraud
  • 90% increase in chargeback win rates  
  • 60% reduction in internal resources dedicated to chargeback management

Read the full case study

See how many more good marketplace transactions you can approve.

Get a walkthrough tailored to your platform: onboarding risk, account abuse, payment fraud, payout threats, refunds, and dispute performance, plus the right friction strategy for both sides of your marketplace.