The system operator transmission owner code (STC) defines the high-level relationship between the National Electricity Transmission System Operator (NETSO) and, currently, the three transmission owners. When the Offshore Transmission regime is active, there will also be Offshore Transmission Owners (OFTOs). The STC has been modified to define the relationship between the NETSO and OFTOs. These changes were made by the Secretary of State at 'Go Active', using powers under Section 90 and 91 of the Energy Act 2004.
Drafting of the changes to the STC has been included in consultation documents, available on the Consultation documents, decisions and responses page.