Automated Clearance Systems (ACS) are currently in use at Manchester and Stansted airports. They are being independently monitored for the UK Border Agency, as well as by the Home Office Scientific Development Branch.
The system can reliably pick out impostors and even distinguish between identical twins. The face matching system uses statistically based algorithms and error rates are in line with system specifications. The system is monitored by UKBA officers, who will examine any passengers rejected by the gate, as well as carrying out random manual checks.