Standing at a boulangerie near the Eiffel Tower and scanning a QR code with your Indian bank app to buy a croissant is no longer a hypothetical. Since France's BPCE group integrated UPI in mid-2023, Indian tourists have been able to pay in euros directly from their rupee accounts without dynamic currency conversion fees.

The National Payments Corporation of India (NPCI) has inked bilateral agreements with more than 10 countries, and the volume of cross-border UPI transactions grew 340 percent year-on-year in the first quarter of 2024. NPCI International CEO Ritesh Shukla calls it "the democratisation of global payments" — a system built on open standards, not proprietary rails controlled by a handful of card networks.

The geopolitical dimension is equally significant. Washington and Brussels have begun studying UPI's architecture as they search for alternatives to over-reliance on Visa and Mastercard in sensitive corridors.