Later this year, payments giant Mastercard plans to open up access to its A2A instant payments technology via a sandbox, promising an environment where UK banks and financial institutions can safely experiment and collaborate across new ways to pay.
Through the launch of the new sandbox, Mastercard hopes to play a significant role in helping to modernise the UK’s A2A payment ecosystem by enabling banks and FIs to test new flows, including retail and digital assets, across person-to-person, person-to-merchant, and business-to-business use cases.
The new sandbox could enable banks and fintechs to implement a ‘five-leg credit transfer’ with confirmation of funds, meaning that a consumer can make a retail real-time payment, with the merchant getting instant confirmation of payment. This functionality is a significant step forward in bringing new ways to pay to the UK market and increasing merchant and consumer choice.
Speaking about the possibilities of the sandbox, Peter Reynolds, EVP of Mastercard real-time payments, explained: “Account-to-account payments in the UK are already an enormous part of the UK’s financial landscape. The Mastercard A2A instant payments Sandbox opens our innovative technology to our partners to develop and test new potential services. Alongside the UK government’s National Payments Vision, we’re setting out a bold vision of the future in A2A real-time payments.”
The sandbox will adhere to modern international ISO20022 standards, which provide several new advantages thanks to the rich data provided, including improvements in the amount of data that can flow alongside the transaction. The rich data allows for new ways to significantly enhance fraud detection and reduction, as well as future advancements.
Modernisation of the UK’s A2A infrastructure comes with significant potential benefits. According to an EY report published in March 2025, enhancing A2A infrastructure could offer a potential £9billion uplift to GDP annually. Mastercard says the sandbox is a first step in showing how this growth can be unlocked, providing the proving ground for new infrastructure capabilities and new products.
Driving payments progress
Toward the end of 2024, the UK government published the National Payments Vision (NPV), which outlines its ambition for the payments sector and how to boost economic growth through the adoption of modern services. The A2A sandbox shows how this can be possible, allowing banks and fintechs to prepare for the next stage in the UK’s payments evolution.
Jana Mackintosh, UK Finance managing director for payments and innovation, also commented: “It’s always exciting to see innovation coming to the market. Mastercard’s sandbox demonstration at our Digital Innovation Summit is a great example of how we can bring the National Payments Vision to life. I hope we’ll see many more industry-led solutions that help drive progress across our payments landscape.”
Alongside supporting the development of new features, the sandbox will also offer insight into the future, showing what a new account-to-account infrastructure can do for the UK. Built on Mastercard’s A2A Instant Payment platform, the cloud-ready solution gives powerful, but simple, front-end tools with a clean user experience and developer portal, while the back-end offers powerful functionality with API access to simplify integration.
