Biometric Interface

A device 200 for communication with a terminal 207 comprises a communication unit 203 for communicating with the terminal, a biometric unit 202 with a sensor 204 for sensing biometric data, and contacts 201 for connecting the device to the terminal. A first physical interface 205 exists between the biometric unit and the contacts and enables communication between the biometric unit and the terminal. A second physical interface 206 exists between the communication unit and the biometric unit and enables communication between the communication unit and the biometric unit. The device is configured such that all contact communications between the terminal and the communication unit are routed through the biometric unit via the first and second physical interfaces. The device may also be capable of contactless communications via antenna 208. The biometric unit may include a multiplexer (MUX) (305, figure 3) configured to multiplex biometric inputs and contact inputs onto the second physical interface.