Mastercard has developed a sandbox where financial institutions can experiment with the latest instant payments technology. The sandbox gives banks access to Mastercard’s fifth generation account-to-account (A2A) real-time payments infrastructure. Within this environment, UK financial institutions can test payment use cases across retail, peer-to-peer (P2P), and B2B transactions. For example, the sandbox will enable institutions to implement a “5-leg credit transfer,” allowing a consumer to make a real-time payment at a merchant with the retailer receiving instant confirmation. According to Mastercard, the merchant and their financial institution would also receive richer data from these transactions, as the sandbox will adhere to the ISO 20022 format. While there are benefits to ISO 20022 adoption, many financial institutions—especially small- to mid-tier banks—have yet to achieve compliance. Beyond the costs associated with upgrading, a key reason for hesitation is concern around risk and fraud. This is where the sandbox model can provide value for highly regulated financial institutions looking to adopt emerging technologies. For example, artificial intelligence has become one of the most transformative technologies in recent years. Yet, many financial institutions worry it could make errors or jeopardize sensitive customer data. In response, Nvidia launched its own sandbox, allowing UK banks to experiment with AI and uncover use cases in a controlled setting. This approach helps financial institutions stay competitive while minimizing exposure to risk.