Statutory information

The electricity you receive from your electricity supplier is delivered using the distribution system owned or operated by your electricity network operator. National Terms of Connection (NTOC) is a connection agreement which governs this process.

Your electricity supplier has been appointed as the agent of your electricity network operator to obtain a connection agreement with you on the national terms of connection. This means that, when you enter into your electricity supply contract with your supplier, you are also entering into a connection agreement with your electricity network operator on these terms.

Supply characteristics

As required by law, the electricity delivered to your premises through our distribution system will normally be at one of the voltages set out below and will have the technical characteristics stated there:

• At 230 volts nominal: normally a single-phase supply, with a permitted range of voltage variation from plus 10% to minus 6%
• At 400 volts nominal: normally a three-phase supply, with a permitted range of voltage variation from plus 10% to minus 6%
• At either of the above voltages: the supply frequency will be 50 hertz, with a permitted nominal variation of plus or minus 1%

Common questions

What is a network operator?

A network operator is a company that transports electricity from generating stations to your property, on behalf of your electricity supplier.

Who is my network operator?

You can use our postcode finder tool to find your local network operator. Note that independent or private network operators also operate networks throughout the country. Your electricity supplier should be able to advise you further.

What are the National Terms of Connection?

Unless otherwise agreed, the National Terms of Connection form an agreement between yourself and the operator of the distribution system through which electricity is conveyed to your premises.

How do the National Terms of Connection affect me?

Unless otherwise agreed, both you and your network operator are legally bound by the National Terms of Connection.

The Distribution Code (DCode) sets out the technical design criteria and procedures applicable to network operators in planning and developing the distribution system.

DCode covers a wide range of requirements and obligations network operators are subject to in meeting their operational Licence conditions:

• Technical aspects relating to the connection and use of the electricity distribution licensees’ distribution networks
• Procedures governing the relationship between a distribution licensee and users of its distribution system for planning and operational purposes in normal and emergency circumstances
• Specific Grid Code compliance obligations for distribution licensees

The Distribution Code is accompanied by two sets of documents known as Annex 1 and Annex 2.

Energy Networks Association (ENA) is responsible for the administration of DCode.

Distributed Generation

Connection guidance and application forms are available from our Resource library. EREC G98 and EREC G99 both apply to connection generation equipment to the network. Visit our Connecting to the networks page for detail on these forms and other supporting documentation.

Modification proposals

All DCode modification proposals are overseen by the Distribution Code Review Panel (DCRP), which ensures consistency across all modifications to the DCode and the resulting documentation. A full set of these documents are available at DCode website and the ENA Engineering Document Catalogue.

Further information about areas currently under revision and open consultations is available from the DCode website.

Code administration

Code Administrators are the point of contact for matters relating to the code, including how to become a party to the code and rules on modifying the code. All Code Administrators act responsibility and comply with requirements laid out in accordance with the Code Administration Code of Practice.

Central Modifications Register

Code Administrators have developed and regularly manage the Central Modifications Register, which details all current modifications across the eleven codes.

The Joint Office of Gas Transporters publishes information regarding transportation charges as required. Indicative and actual charges are published on their website, along with any consultation paper.

Find out more on the Joint Office of Gas Transporters website.

The CiC Code of Practice governs the way in which our network operators provide input services to facilitate competition in the electricity connections distribution market.

Ultimately, it helps to create more choice for customers in selecting a connection provider.

The CiC Code of Practice is approved by Ofgem and includes a process for review so the code can evolve over time. This includes an industry panel with representatives from across the industry – network operators, independent network operators and independent connection providers –charged with facilitating the code’s objectives and overseeing proposed modifications.

Gas Transporter procedures is no longer produced or hosted by ENA. Please contact Future Energy Networks (FEN) for further information or visit the FEN publications website (external link).