Mastercard is expanding access to its fifth generation account to account (A2A) instant payments sandbox to UK banks and financial institutions, aiming to strengthen the UK’s A2A payments ecosystem.

From late this year, the offering will enable UK banks and financial institutions to test, validate, and collaborate on new payment methods using Mastercard’s payment infrastructure. Participants will be able to explore new payment flows, including retail and digital business applications, across person to person, person to merchant, and business to business use cases by leveraging Mastercard’s A2A switching technologies.

The cloud ready sandbox complies with ISO 20022 standards and will allow organisations to implement a "five legged credit transfer" with confirmation of funds. This means consumers can make retail payments in real time while merchants receive immediate payment confirmation.

Mastercard stated that the sandbox will enhance the volume of data accompanying transactions, which will also improve fraud detection and prevention.

The initiative aligns with the UK government’s National Payments Vision (NPV), published last year, which outlines ambitions for the payments industry and strategies to drive economic growth through modernised services.

A March 2025 EY report highlighted that modernising the UK’s A2A infrastructure could boost GDP by up to £9 billion annually.

“The A2A sandbox demonstrates how this can be achieved, enabling banks and FinTechs to prepare for the next phase of the UK’s payments evolution,” Mastercard said in a statement.

Peter Reynolds, executive vice president of Mastercard Real Time Payments, commented on the sandbox’s potential, noting that A2A payments already play a significant role in the UK’s financial landscape.

“The Mastercard A2A instant payments sandbox provides our partners with access to innovative technology for developing and testing new services. Together with the UK government’s National Payments Vision, we are shaping an ambitious future for A2A real time payments,” he said.

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