The UK regulator; SARG Policy 120 is its standing approval policy for aerodrome remote towers.
The UK Civil Aviation Authority regulates remote tower approvals in the UK. It consulted on a draft approval policy through CAP 1620 (2017) and now maintains SARG Policy 120, Policy for Approval of Aerodrome Remote Towers, version 4.0 published August 27, 2021, covering single and multiple mode (sequential and simultaneous), change management, licensing, camera systems, human factors, MET, security, and reliability. The operational anchor under this framework is London City, the first major international airport fully controlled by a remote digital tower, live since 2021.