A card may be formed using two or more printed circuit boards. Each printed circuit board may include one or more RFID antennas, RFID chips and a processor. A processor on a board may transfer data to one or more RFID chips on the same board. Alternately, a processor on a board may transfer data to one or more RFID chips on a different board via conductive terminals between boards. Data stored in one or more RFID chips may be erased after being communicated to an RFID device via an RFID antenna or after a configurable timeout period elapses. A card and a mobile device may include more than one RFID antenna to increase efficiency, reliability, and/or a number of data channels that may be communicated.