Basic command unit
A Basic Command Unit is the largest unit into which territorial British Police forces are divided. BCU replaces the earlier terms Sub-Division and Division that had been in use since the 1880s. BCUs may alternatively be called an Area Command or a Division. They will also contain smaller, more local teams which are often called a Local Policing Unit or a Local Policing Team. There are 228 BCUs in England and Wales.
Most forces are divided into at least three BCUs and some have many more. Most BCUs are further subdivided into smaller units. The BCU is usually commanded by a Chief Superintendent.
Metropolitan Police
Until recently the Metropolitan Police used the term Borough Operational Command Unit for regional units within Frontline Policing, the subdivision of the Met responsible for day-to-day policing within the 32 London boroughs.Between 2017 and 2019 the 32 BOCUs were reorganised to form 12 new Basic Command Units, each incorporating between two and four of the original BOCUs.
The term Operational Command Unit is used for specialised units, for example the Aviation Security OCU.