The recent uproar over potential charges for using the Unified Payment Interface (UPI) can perhaps be seen as a measure of its success.The recent Reserve Bank of India paper also examined charges for other instruments, such as credit and debit cards, which did not lead to a similar level of popular debate. The UPI platform has left these instruments far behind in enabling digital transactions, accounting for over 60 per cent of transactions in 2021-22 compared to less than 6 per cent in 2017-18. Card transactions have seen their use erode to a single-digit share over the same period (chart