This guide addresses the implications of APP (Authorised Push Payment) fraud liability for banks, particularly in light of the UK Government's 2023 Fraud Strategy report. It outlines the challenges financial institutions face as they prepare for mandatory reimbursement of fraud victims, effective from October 2024. The guide discusses the need for banks to implement robust methodologies to manage this liability, emphasizing the importance of risk scoring payments and considering the false positive rate in fraud detection. It details how advancements in artificial intelligence and fraud detection APIs can assist banks in assessing transaction risks and automating fraud detection processes. The document also highlights the regulatory landscape, including the roles of the Financial Conduct Authority (FCA) and the Payment Systems Regulator (PSR), and the need for banks to collaborate with payment services providers to enhance fraud prevention strategies. Overall, it serves as a comprehensive resource for banks to navigate the evolving landscape of APP fraud liability.