Direct answer. UPI (Unified Payments Interface) is India's instant 24×7 digital payment system. ₹0 cost for P2P. 16 billion+ monthly transactions (largest globally). Apps: GPay, PhonePe, Paytm, BHIM. UPI Lite for < ₹500 (faster). UPI 123Pay for feature phones. Cross-border live in UAE, Singapore, France, Bhutan, Sri Lanka, Mauritius.
Call 08045163666 → IVR-based payment, no internet needed.
Settings → UPI Lite → Enable. Top up ₹2,000. Use for < ₹500 instant offline.