Debit Card

ℹ️ Refer to theAPI Reference for full request and response examples.

Debit card payments are automatically enabled once your affiliation is active.

🔐 Debit Card Authentication (EMV 3DS 2.2)

All debit transactions must go through authentication using the 3DS 2.2 protocol, as required by card brands and issuing banks. This ensures that the buyer is the legitimate cardholder, enhancing security and reducing fraud risk.

We use the EMV 3DS 2.2 protocol — a secure, browser-based flow that authenticates the cardholder while maintaining a smooth checkout experience.

sequenceDiagram
    participant Buyer as 🧑 Buyer
    participant Merchant as 🛒 Merchant Platform
    participant ThreeDS as 🔐 3DS Server
    participant Issuer as 🏦 Brand & Issuer
    participant A55API as 🧩 a55 API

    Buyer->>Merchant: 1. Chooses to pay with debit card
    Merchant->>ThreeDS: 2. Starts 3DS authentication
    ThreeDS->>Issuer: 3. Requests auth from brand/issuer
    Issuer-->>ThreeDS: 4. Returns challenge or frictionless result
    Buyer->>Issuer: 5. Completes challenge (if required)
    Issuer-->>ThreeDS: 6. Authentication result
    ThreeDS-->>Merchant: 7. Sends 3DS result
    Merchant->>A55API: 8. Sends transaction with 3DS data
    A55API->>Issuer: 9. Authorization request
    Issuer-->>A55API: 10. Authorization result
    A55API-->>Merchant: 11. Final status
    Merchant-->>Buyer: 12. Confirms payment