A method and system for prepaying wireless telecommunications charges utilizes computer hardware and software including, for example, a user's mobile phone, a mobile operator's interactive voice response unit, a mobile payments interactive voice response unit, SMS, test messaging, email, ATM, kiosk, the Internet, and/or WAP or the like, a mobile payments engine, a mobile operator's prepaid billing system, a subscriber database, a payment gateway, and a transaction processing platform. The mobile payments engine receives information identifying a user's wireless telecommunication device via the mobile payments interactive voice response unit, passes the information to the mobile operator's billing system with a request for validation of a mobile account for the user, and if validation is received, the mobile payments engine receives financial source account and user identity verification information from the user, assigns a mobile personal identification number for the user, and arranges a credit from the source account to the user's mobile account.