The payment integration process involves selecting a suitable payment gateway, creating a merchant account, and obtaining API credentials. Businesses can choose between a hosted payment page or API integration, depending on technical expertise. The development team then integrates the chosen method, conducts thorough testing, and ensures security compliance with PCI DSS. Once live, businesses monitor transactions and maintain the integration to adapt to changing requirements. A successful payment integration streamlines the payment process and enhances customer trust and conversion rates.