Which non-card payment system initially used ISO 8583 message standards for payment messages?

The non-card payment system that initially used ISO 8583 message standards for payment messages is the Faster Payments Service. ISO 8583 is primarily recognized for its role in facilitating electronic transactions and is closely associated with card payment systems. When the Faster Payments Service was developed, it incorporated this standard to help streamline transaction messaging, allowing for real-time or near-real-time payment processing within the UK banking sector.

This decision to utilize ISO 8583 provided a familiar framework for technical integration with existing systems, making it easier for financial institutions to adapt to the new payment processing capabilities without extensive system overhauls. The real-time nature of Faster Payments necessitated a robust messaging system capable of handling a higher volume and velocity of transactions compared to traditional systems.

Other options like CHIPS, SWIFT, and ACH utilize different messaging standards that are more suited to their specific operating requirements and transaction types. CHIPS and SWIFT, for instance, are focused on international payments and have protocols that are distinct from ISO 8583. ACH typically uses its own format and standards for batch processing transactions, emphasizing efficient handling of electronic funds transfers rather than real-time processing.