We present an overview of the development of the SecurePhone mobile communication system in which multimodal biometric authentication gives access to the system’s built-in e-signing facilities, enabling users to deal m-contracts using a mobile call in an easy yet secure and dependable way. Authentication uses an neutral biometrics: the user reads a prompt into a camera and microphone, and signs on a touch screen. The state of the art techniques used for each biometric modality were initially developed using the benchmark databases BANCA (audio-visual) and BIOMET (signature). A suitable PDA was then selected and a multimodal database was recorded on the device itself. Several fusion techniques were tested for biometric evidence combination. Best performance achieved for voice, face, signature and fused modalities was 2.3, 17.3, 4.3 and 0.6% EER for BANCA/BIOMET and 3.2, 27.6, 8.0 and 0.8% EER for the PDA database.