Adyen saysHard decline
31Issuer Suspected Fraud
What it means
Suspected fraud
The issuer or a fraud system flagged the payment as suspicious.
What to do
Do not retry automatically. Review the order, and let a genuine shopper confirm with their bank.
Don't retry as-isWho can fix it: The card issuer
Yuno response codeFRAUD_VALIDATION
Source:Adyen docs — Refusal reasons
Reference only. Codes and descriptions come from each provider's public documentation. The Yuno response code is a reference mapping and does not guarantee how a specific transaction is processed.