We are a separate company

On 1 April the Electricity System Operator became a legally separate company within the National Grid Group. Find out more about what this change means.

Grid Code

The Grid Code is the technical code for connection and development of the National Electricity Transmission System (NETS).


The Grid Code specifies technical requirements for connection to, and use of, the NETS. Compliance with the Code is a requirement under the Connection and Use of System Code (CUSC).

We maintain the Grid Code and serve as its administrator. All changes are subject to industry consultation and approval by Ofgem.

Find out more about connecting to the NETS in our Electricity connections pages.

Please refer to the Electrical standards page for documents and details relating to electrical standards and specifications for electronic data communications facilities.

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

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Grid code modification guidance and documents

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