India's UPI miracle faces its first real test: who pays for it?

India has paved the way for charging merchants a fee on UPI transactions

India's Unified Payments Interface (UPI) has become a global payments giant, processing over 23 billion transactions a month, but the system's free-for-merchants model is under review. The government is considering a small fee on large transactions at big businesses to sustain the network, a move that could generate up to a billion dollars. Yet economists warn that charging small merchants could slow adoption, as merchant acceptance has been a key driver of UPI's growth. The challenge is to make UPI financially viable without undermining the conditions that made it ubiquitous.