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System Operator Transmission Owner Code

The System Operator Transmission Owner Code (STC) defines the relationship between the transmission system owners and the system operator.

The System Operator-Transmission Owner Code (STC) defines the relationship between the transmission system owners and National Grid as the National Electricity Transmission System Operator (NETSO).

The STC procedures (STCPs) set out the roles, responsibilities, obligations and rights of each party in further detail. We are the code administrator for the STC and maintain the Code. All changes are subject to industry consultation and approval by Ofgem.

If you can't find what you're looking for here, please contact us and we will try to assist you.

STC modification guidance and documents

These documents will help you understand how to propose a modification.