Any bank to any bank transfers in India are literally instant now, via UPI or Unified Payment Interface. A central office gets all incoming requests, & settles

Any bank to any bank transfers in India are literally instant now, via UPI or Unified Payment Interface. A central office gets all incoming requests, & settles the txns. Users & Merchants get id like user@bank, merchants can send a collect request; users can send money, protected through 4-8 char long pin.