To ask the Secretary of State for the Home Department what assessment his Department and its agencies have made of the accuracy of the data stored on the Automatic Number Plate Recognition databases for which they are responsible; and whether he has made a recent estimate of the proportion of entries on such databases which contain incorrect information. (318115)

Automatic Number Plate Recognition (ANPR) systems are owned and operated by individual police forces. Number plates read by police force cameras are fed into local Back Office Facility (BOF) databases before being forwarded to the National ANPR Data Centre (NADC) which is managed by the National Policing Improvement Agency (NPIA).

Chief Constables are “data controllers in common” for ANPR data and are responsible for the accuracy of the data. The National ACPO (Association of Chief Police Officers) ANPR Standards (NAAS) set out clearly the criteria for ANPR data quality.

While no estimate has been made of the proportion of incorrect interpretations of number plates, an image of the plate is stored with each record of a sighting. The plate text is never used without the image being viewed and such information would not be acted upon without further information or intelligence.