UPI as Public Digital Infrastructure: Re-thinking Regulatory Models under the Payment and Settlement Systems Act, 2007

India's Unified Payments Interface has achieved the status of a critical infrastructural component of the economy after passing beyond a successful retail payments technology and innovation phase. This Article tackles the question that has arisen as a result of this development: a law that permits and oversees payment systems is unable to answer the public law queries that exist when a payment rail becomes the foundation of commerce, welfare, and digital governance. The Article uses doctrinal legal research by focusing on the Indian legal system, the Payment and Settlement Systems Act of 2007, and various Reserve Bank of India circulars and documents, as well as contemporary National Payments Corporation of India documents. The Article examines major judicial rulings on the right to privacy, the imposition of consumer harm, the control of fraud, and competition. The Article identifies and analyzes the current legal system's characteristics pertaining to settlement. The legal framework regulates authorization, supervision, and the finality of settlement, but it is unable to, or has chosen not to, codify access neutrality, transparency in rules and processes, procedural and substantive due process of control, accountability of platforms, and data governance. The scattered legal frameworks on privacy and data protection, proportionality, competition, and consumer welfare provide a cohesive legal framework for improvement. The Article argues that in Indian legal systems, the Unified Payments Interface is a public digital platform, and therefore, fair access, transparency, resilience, and redress as well as integrated supervision in digital payment systems apply. The primary argument of the Article is that in payment systems, scale changes the legally defensible position in payment systems. There is a demand for Indian payments laws to incorporate the logic of structuring payment systems as a social contract in place of payment systems laws.