What is the biometric border? How did it emerge and to what extent have biometric technologies changed borders and the experience and articulation of the bodies that cross them? Although the use of biometrics in border security and visa and mobility management are presented as enabling verification and authentication of political identity, deeper trends towards what for lack of a better term we might refer to as a ‘biometric state’ are part of this story. It is as much about the increasing interoperability and interchangeability of border security and identity management tactics that biometrics promises, as it is about proliferating and enhancing sovereign power as global commerce and mobility challenge the state’s resilience. Referred to as emergency or exception, biometric borders are instrumental facilitators in the proliferation and permanence of this discretionary sovereign power.