E-commerce Payment Systems and Payment Gateway Workflow

Common payment systems

• Credit/debit cards: payment is authorized through the card network and issuer.
• UPI: instant account-to-account payments using a UPI app, ID or QR code.
• Net banking: customer authorizes payment through a bank's online service.
• Digital wallets: stored value or linked payment methods are used through a wallet provider.
• Bank transfer: funds move between bank accounts.
• Cash on delivery: payment is collected when goods are delivered; settlement happens later.
• EMI/Buy Now, Pay Later: eligible customers pay in installments subject to provider terms.

Payment gateway: securely connects a merchant's checkout to payment processors, banks or payment networks. A gateway may tokenize sensitive details and return the transaction result; it does not itself guarantee that every payment is approved.

Workflow: customer confirms the order; merchant creates a payment request; gateway securely forwards it to the relevant processor/network; issuer or bank authenticates and authorizes the payment; the result returns through the gateway; merchant updates the order and sends confirmation. Capture and settlement may occur immediately or later depending on the payment method.

Security: use HTTPS/TLS, tokenization, PCI DSS-compliant providers, fraud detection and strong customer authentication where required. Never store card security codes.

Conclusion: Multiple payment options improve convenience. A gateway coordinates secure communication and authorization between the merchant and payment ecosystem.