List of ROC Group Headquarters and UKWMO Sector controls

This is a list of the locations for former Royal Observer Corps (ROC) Group Headquarters and the United Kingdom Warning and Monitoring Organisation (UKWMO) sector controls that received information from ROC posts by dedicated GPO/BT landlines. Clusters of posts also had VHF radio communications with HQs and sector controls, in case of land-line failure, from the cluster Master Posts.
The Royal Observer Corps was a civil defence organisation operating in the United Kingdom between 29 October 1925 and 31 December 1995, when the Corps' civilian volunteers were stood down. (ROC headquarters staff at RAF Bentley Priory stood down on 31 March 1996). Composed mainly of civilian spare-time volunteers, ROC personnel wore a Royal Air Force (RAF) style uniform and latterly came under the administrative control of RAF Strike Command and the operational control of the Home Office. Civilian volunteers were trained and administered by a small cadre of professional full-time officers under the command of the Commandant Royal Observer Corps; latterly a serving RAF Air Commodore.