An RF recurrent billing system in which an account number associated with a recurrent billing account is stored within an RF transaction device. The user of the RF transaction device may present the device for completing a transaction, and the transaction, if successfully completed, is billed to the...http://www.google.com.hk/patents/US7725427?utm_source=gb-gplus-share專利 US7725427 - Recurrent billing maintenance with radio frequency payment devices
