Self-Validation Testing: the launch of customer collaboration on the NPA

The New Payments Architecture (NPA) will be the biggest upgrade the UK payment systems have seen in a generation. Our testing strategy has therefore been meticulously designed to support the programme in ensuring that the NPA framework can be validated across the entire ecosystem.

In April 2023, we launched the first phase of this strategy, Self-Validation Testing (SVT), that ensures customer readiness for the ISO 20022 messaging standard. Presenting the first opportunity for customers to interact with the NPA solution, here we examine all you need to know about this exciting stage in the NPA journey.

What are the objectives of SVT?

The New Payments Architecture includes, as a key principle and requirement, the adoption of ISO 20022 as the payments messaging standard. With enhanced data fields and the potential to create a single common language for payments globally, it will accelerate the integration and digitisation of the payments ecosystem, increase innovation and boost the entire payments value chain.

SVT allows customers to autonomously validate their ISO 20022 messages against the NPA message standards and solution design, and ensures that they can submit and respond to different types of payment and non-payment messages.

How does SVT work?

Launched on 24 April 2023, this first testing stage is a two-phased approach, with two customers and a further seven in the pipeline. With an initial scope focus on priority payment (Single) via XML submission, which will be extended to multi-payments and JSON messaging via API (application programming interface) at appropriate intervals, it allows customers to validate their solution’s capability to send, process and receive ISO 20022 payment and non-payment messages through testing with a message simulator.

The configuration of the simulator matches that of the NPA functionality and is aligned to the latest set of published standards. Testing customers are able to validate their solution’s adherence to the platform through the simulator using pre-configured test scenarios, acting as the NPA core and another customer.

Not only does this self-service model provide customers with an unparalleled level of autonomy by reducing dependency on ‘test slots’, but it further offers feedback to customers testing their solution in ‘real-time’. Customers are then able to raise any NPA-related defects or issues encountered during testing to our central support team which will then be managed and addressed by us. In this way, we are able to make informed decisions on the overall solution model by discovering and sharing relevant information pertaining to the values and threats of the testing model, further using this information to provide regular test progress reports to relevant stakeholders.

David Morris, Chief Technology Officer, says:

“The SVT allows customers to connect to a technical representation of the NPA for the very first time and test those ISO 20022 messages, both as a sending and receiving organisation. It represents a ‘launch moment’ for the programme as customers begin their transformation from the existing Faster Payment System to the data-rich NPA product types.
“The ISO standard for NPA introduces many new data fields, greater structure and choices with optionality that will help NPA deliver on its key objectives and fuel new initiatives such as payment purpose, enhanced identification of who’s involved in the payment value chain, confirmation and traceability of payment status’ and supports our wider fraud prevention programme drawing from the same data dictionary and reference data set.  
“In the coming weeks, the simulator will be enhanced to more fully emulate the proposed behaviour of the NPA’s design and allow our customers to begin functionally testing their implementations with the full range of message exchanges and interactions with NPA and other customers.”

What’s next?

Alun Morgan, Head of Quality Assurance and Testing, details the much-awaited next stage of testing in the NPA journey.

“As we progress SVT with our customers, we will look ahead to planning for the next test phase for NPA, which is Release Functional Testing. In contrast to SVT, this is an internal test phase and will be the first time Pay.UK will get to test the actual Vendor NPA solution, once they have been selected. Pay.UK needs to validate the solution against the necessary requirements before customers can interact with the NPA platform. The testing required for this phase will be crucial in the success of the programme.  Release Functional Testing, like other phases that follows it, will be the culmination of many years of planning and preparation and for the Pay.UK Quality Assurance and Testing team the most exciting test phase.”

We invite you to keep up to date with the latest in the testing journey and take part in our testing working group. To find out more, contact