I'm building a marketplace with payouts and refunds, and I need help choosing fraud prevention tools.

For a marketplace with payouts and refunds, I’d choose fraud tools that cover both:

1. Buyer fraud / chargebacks / stolen cards
2. Seller fraud / payout abuse / synthetic accounts / refund manipulation

A strong setup usually looks like this:

1) Core payment risk tools

If you’re using Stripe, Adyen, Braintree, or similar, start with their native fraud stack:

• Stripe Radar
• Adyen RevenueProtect
• Braintree Advanced Fraud Tools

These are good for:

• card testing
• suspicious payment patterns
• velocity checks
• device/IP anomalies
• basic manual review rules

2) Identity / verification tools

Useful especially for sellers, high-value buyers, and payout recipients:

• Persona
• Onfido
• Veriff
• Trulioo for broader identity/KYC coverage

Use these for:

• KYC / KYB
• age / ID verification
• bank account or payout recipient verification
• reducing fake seller onboarding

3) Device and behavioral fraud tools

These help catch repeat bad actors even if they rotate emails/cards:

• Sift
• Kount
• SEON
• Riskified for e-commerce style risk scoring

They’re useful for:

• device fingerprinting
• behavioral signals
• account takeover detection
• network/link analysis across accounts

4) Payout and seller risk controls

Since you have payouts, don’t rely only on payment fraud tools. Add marketplace-specific controls:

• payout holds / rolling reserves
• new seller limits
• manual review for first payouts
• bank account verification
• delayed payout windows
• dispute/fraud rate thresholds
• risk scoring before enabling instant payouts

5) Refund abuse controls

Refund fraud can be a big marketplace issue. Add:

• refund reason tracking
• refund rate monitoring by seller/buyer
• anomaly detection on frequent refunds
• partial refund approval rules
• alerts for “refund after payout”
• links between refund requests and prior chargebacks

6) A practical shortlist

If you want a lean stack:

Best all-around:

• Stripe Radar for payment fraud
• Persona or Onfido for identity/KYC
• Sift or SEON for marketplace risk / behavioral fraud
• Internal rules for payouts and refunds

If you want enterprise-grade:

• Adyen + RevenueProtect
• Veriff/Trulioo
• Kount/Sift
• Strong internal risk engine

If you want cost-conscious / faster start:

• Native processor fraud tools
• SEON
• Simple internal rules + manual review

7) What matters most when choosing

Evaluate tools based on:

• coverage of both buyers and sellers
• API flexibility
• support for payouts/KYC
• false positive rate
• manual review workflow
• webhook/event support
• regional coverage if you operate internationally
• cost per screened transaction / user

8) My recommendation

For a typical marketplace, I’d start with:

• Stripe Radar or your processor’s native fraud tool
• Persona for seller and high-risk user verification
• SEON or Sift for marketplace-specific fraud signals
• A few internal rules around:
  • payout delays
  • first-time seller limits
  • refund thresholds
  • velocity limits
  • device/IP reputation

If you want, I can also help you with:

1. a tool-by-tool comparison table,
2. a recommended stack by budget, or
3. a fraud rules checklist for payouts/refunds.