ISO/IEC 19784-4:2011 specifies a biometric sensor interface for a Biometric Service Provider (BSP, see ISO/IEC 19784-1). The interface supports a BSP wishing to provide the BioAPI Service Provider Interface (SPI) functions, whilst removing device handling activity from the BSP. ISO/IEC 19784-4:2011 provides an interface that can be used by all types of biometric sensor, including _inter alia_ image streaming sensors (infrared, face, iris, finger, etc.), voice streaming sensors and digital tablets providing dynamic signature data.

It is not in the scope of ISO/IEC 19784-4:2011 to define security and privacy requirements for capturing and transferring of biometric data across the Sensor Function Provider Interface (SFPI).