National Terms of Connection
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.
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%
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 the postcode finder 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.
UK Power Networks (ENA Member)
Electricity Network Co.
Electricity North West Limited (ENA Member)
INPL (ENA Member)
ESP ELECTRICITY LTD. (ENA Member)
Scottish & Southern Electricity Networks (ENA Member)
SP Energy Networks (ENA Member)
Western Power Distribution (ENA Member)
Electricity distribution code
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
Energy Networks Association (ENA) is responsible for the administration of DCode.
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.
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 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.
Gas distribution code
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.
CiC Code of Practice
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 procedure: Requesting gas service pipe pressures and capacity information (GDN/PM/GT1)
Gas Transporter documentation can be found in our Resource library.
Regulation 6(8) of the Gas Safety Management Regulations 1986 imposes the following duty on a person conveying gas in a network...
“where he is requested to do so by a person proposing to carry out work in relation to a gas fitting, provide him with information about the operating pressures of the gas at the outlet of a service pipe”
While this regulation is applicable to persons undertaking work downstream of the emergency control valve (ECV), which terminates the end of a gas supply pipe (for example when intending to install a gas supply meter installation), there are other categories of work such as work on service pipes where the provision of information about the operating pressure of gas is also important.
Management Procedure for Requesting Gas Service Pipe Pressures and Capacity Information (GDN/PM/GT1) outlines how the information ought to be requested and provides the documentation required.
Gas transporter procedure: Requesting a gas transporter (GDN/PM/GT2)
Gas Transporter documentation can be found in our Resource library.
- Authorise the setting and sealing of regulators
- Authorise the installation of a meter by-pass
- Approve a meter housing design
The Gas Safety (Management) Regulations 1996 place a duty on a Gas Transporter (GT) to ensure that gas is at a suitable pressure to ensure the safe operation of any appliance that a consumer could reasonably expect to operate.
The Gas Safety (Installation and Use) Regulations 1998 require that the person who installs or adjusts a regulator shall ensure that it is adequately sealed. This seal is to prevent the setting from being adjusted or interfered with. No person except the GT or a person authorised to act on his behalf shall break the seal applied to the regulator.
The HSE have considered that the Gas Safety (Management) Regulations 1996 should be taken as meaning that a GT is deemed to have ‘control of the meter regulator’. This should ensure the integrity of the system downstream of the meter regulator, and as far as reasonably practical, ensure that the downstream system is supplied with a satisfactory pressure to ensure the safe combustion of gas at a gas appliance.
The Unified Network Code requires that following approval by a Gas Shipper, the provision and use of a meter by-pass shall be approved by the GT.
The Gas Act 1986 (As amended) requires that where a meter is to be installed in a meter house, the type and construction of the meter house shall be approved by the GT. Failure to obtain approval could result in the GT refusing to connect, or as the case maybe, disconnect the gas supply to the consumer’s premises.
Where a meter installation is or is intended to be connected to a network operated by a GT, ‘Authorisation’ applies to any activity associated with:
- Initial setting of a regulator, sealing or breaking a seal and adjustment of a regulator and any associated pressure control or protection devices
- Installation of a meter by-pass
- Design of meter housing
Management Procedure for Requesting a Gas Transporter (GDN/PM/GT2) [link] provides details on how to make applications and shall be used by a Meter Asset Manager (MAM) to request an Authorisation.
Gas transporter procedure: Sealing of equipment to protect against theft of gas and tampering (GDN/PM/GT4)
This Management Procedure is for use by Registered Users of the Uniform Network Code, independent Gas Transporters’ (iGT) Uniform Network Code (UNC) and their representatives.
This procedure specifies acceptable means to achieve the “isolation” of the Supply Meter Point under the terms of the UNC, section G and appropriate section of the iGT UNC.
The supply of gas at a meter installation may cease under the terms of the Network Code or under Schedule 2B of the Gas Act 1986 as amended 1995. The terms under which a supply of gas may cease are:
- Discontinuance – An act by a gas supplier as a means of stopping the flow of gas at a gas supply meter point.
- Disconnection – An act by a GT to ensure that gas cannot be off-taken through a supply meter point.
The options detailed in this procedure provide an acceptable means to protect against the theft of gas and tampering in both domestic and non-domestic installations and are acceptable to the GTs.
Adherence to this procedure is a precondition of amending the Supply Point Register to set the status of the Supply Meter Point to “isolated” in accordance with the requirements of the relevant GTs.