The Modernised API builds on the existing error handling from the Real-time Retail Payments Platform (RPP) by keeping the familiar reason code and status so there’s consistency for developers.
 

What’s new is a set of enhanced fields that make troubleshooting faster and clearer:
 

• name – A human-readable identifier that helps quickly categorise the error.

• description – A detailed explanation of what went wrong, giving more context.

• details – Optional insights like validation issues or missing parameters to help pinpoint the problem.

• additionalCode – An optional field for extra response codes, often used when third-party services are involved.
   

These improvements offer a more transparent and developer-friendly experience, making it easier to identify, troubleshoot, and resolve issues with confidence.