After six years of free use, India will begin charging a fee for larger transactions under its popular Unified Payments Interface. Will the move push some merchants back to demanding cash? ▻ ↧ Big to get bigger: India's UPI fee shift to entrench dominant incum... Walmart-backed PhonePe and Google Pay could earn hundreds of millions of ​dollars a year in extra revenue from India's move to allow merchant fees on its widely used Unified Payments Interface (UPI) digital payment network, entrenching the dominant apps' lead over ‌smaller rivals.