Payment volumes on the Unified Payments Interface (UPI) fell on a month-on-month (m-o-m) basis in April, according to data released by the National Payments Corporation of India (NPCI) on Wednesday. The number of UPI transactions dropped a little over 2% month-on-month (m-o-m) to 781.79 million in April from 799.54 million in March. The value of transactions continued to grow, rising 6.4% m-o-m to `1.42 lakh crore. On a year-on-year (y-o-y) basis, however, there was a 311% jump in UPI volumes in the month of April, while the aggregate value of transactions shot up 426% y-o-y. NPCI also released data on transactions made using its Bharat Interface for Money (BHIM) app in April. The volume of transactions made using BHIM rose 1.5% m-o-m to 15.15 million, while their value increased 2.6% to `6,584 crore. In April, BHIM's share in UPI transactions stood at around 2%, unchanged from the previous month. Since its launch in August 2016, UPI has seen two waves of exponential growth \u2014 one in early 2017 following the launch of the Bharat Interface for Money (BHIM) app and another with Google Tez and Paytm entering the UPI ecosystem in September and November 2017 respectively. What can likely drive the next round of growth in UPI volumes would be the full-fledged launch of payments for all WhatsApp users. In February 2018, investment bank Credit Suisse said in a report that the entry of WhatsApp into the UPI ecosystem could lead to some shake-up. \u201cWhatsApp, with 230 million daily average users, is by far the most popular app in India and as it soon plans to integrate a payments button, digital payments are set to explode and we estimate a US$1 trillion market over the next five years,\u201d it said.