What is UPI?
Also known as: Unified Payments Interface
UPI (Unified Payments Interface) is India's real-time payment system, allowing instant bank-to-bank transfers from a phone using a UPI ID or QR code.
UPI carries the largest share of digital transaction volume in India and generally costs merchants very little or nothing on many flows, which makes it the method most worth optimising for at checkout.
For sellers the practical point is placement: if UPI is buried behind card entry in your checkout, you are adding friction to the method most of your customers want to use.