India offers an offline UPI payment facility using Unstructured Supplementary Service Data (USSD) technology, accessible by dialing *99#. This service allows users to send money, check balances, and view transactions without an internet connection, relying instead on basic GSM signals. Supported by the NPCI, it works on all feature phones and smartphones, benefiting users in areas with poor connectivity or those using basic mobile devices. Transactions are confirmed using a UPI PIN after entering recipient details and the amount.