Assistant chief constable
Assistant chief constable is the third highest rank in all British territorial police forces, as well as the British Transport Police, Ministry of Defence Police and Civil Nuclear Constabulary.
Each force has between one and six assistant chief constables. They are the lowest officers at chief officer level, below the chief constable and deputy chief constable, and rank immediately above chief superintendents. Assistant chief constables usually hold portfolios. In larger forces, ACCs may be given responsibilities for policing major territories within the force area.
Senior police civilian staff hold equivalent status and are generally known as assistant chief officers.