What does the interoperability of Australia's NPP rely on?

The interoperability of Australia's New Payments Platform (NPP) relies on ISO 20022 messaging standards. ISO 20022 is a global standard for electronic data interchange between financial institutions, providing a common platform for the development of messages in a wide range of financial services. This standard ensures that different payment systems can communicate effectively with each other by using a consistent structure for data exchange.

By adopting ISO 20022, Australia's NPP facilitates seamless transactions across various financial institutions and systems, promoting efficiency and reducing errors in payment processing. The use of this standard allows for richer data in transactions, which can enhance the overall user experience and support better compliance with regulatory requirements.

The other options do not provide the necessary framework for interoperability within the NPP. For example, HTML messaging standards are designed for web content and do not cater to financial transaction data. SMTP protocols are primarily used for email transmission and are not suitable for financial messaging. Traditional DNS systems are essential for resolving domain names but do not relate to the standards required for financial data interchange.