Undercover policing is a covert tactic used by the Police to obtain evidence and intelligence. It is also used to detect crime and disorder and help maintain public safety.

Undercover policing is a lawful and ethical tactic and when applied rightly can be very effective tool. In order to ensure it is kept this way, Authorised Professional Practice (APP) has been developed and used by Law Enforcement Agencies (LEAs) across the United Kingdom.

There is an undercover accreditation process that has been developed to provide an assessment of whether the management and governance of undercover units are effective in supporting safe, ethical and lawful undercover operations.

Undercover operatives (UCOs) are deployed as covert human intelligence sources (CHIS) in authorised investigations. There are three different types of UCOs, Undercover foundation(UCFs), Undercover advanced operatives (UCAs) AND Undercover online operatives (UCOLs). All must go through vigorous training and go through a robust selection process.