Licensed electricity distribution businesses, or Distribution Network Operators (DNOs) in Great Britain, are obliged under Condition 21 of their licences to maintain a Distribution Code detailing the technical parameters and considerations relating to connection to, and use of, their electrical networks.

DNOs

Electricity North West
www.enwl.co.uk

National Grid Electricity Distribution
www.nationalgrid.com/electricity-distribution

Northern Powergrid
www.northernpowergrid.com

Scottish and Southern Electricity Networks
www.ssen.co.uk

SP Energy Networks
www.spenergynetworks.co.uk

UK Power Networks
www.ukpowernetworks.co.uk

IDNOs

Eclipse Power Networks
www.eclipsepower.co.uk

Energy Assets Networks Limited
www.energyassets.co.uk

ESP Utilities Group
www.espug.com

GTC (comprising both ETCL and IPNL licences)
www.gtc-uk.co.uk

Fulcrum Electricity Assets Limited
www.fulcrum.co.uk

Harlaxton Energy Networks Limited
www.harlaxtonenergynetworks.co.uk

Last Mile
www.lastmile-uk.com

Leep Electricity Networks Limited
www.leeputilities.co.uk

Murphy Power Distribution Limited
www.murphygroup.co.uk

UK Power Distribution Limited
www.ukpowerdistribution.co.uk

Utility Assets Limited
www.utilityassets.co.uk

Vattenfall Networks Limited
https://networks.vattenfall.co.uk

The GB Distribution Code

All DNOs currently operate the same version of the Code, and the Code is maintained by the Distribution Code Review Panel. All modifications to the Code are approved by Ofgem.

Issue 57: Effective from 01 October 2024

The revised version of the GB Distribution Code incorporates amendments to facilitate the implementation and requirements of the electricity System Restoration Standard and associated Grid Code alignment text.

Copy of Distribution Code Issue 57 can be found here

Click here for previous versions of the GB Distribution Code

Distribution Code User Guide

The guide gives a high level overview of the Distribution Code, and is aimed at anyone with an interest in the Distribution Code. It contains information about the regulatory structure in Great Britain and Europe and also provides a simple explanation of the various sections of the Distribution Code.

Click here to download the current version of the GB Distribution Code User Guide

Annex 1 and Annex 2 Documents

Some requirements of the Distribution Code are implemented through other industry documents. They are listed in Annex 1 of the Distribution Code, and are mostly Engineering Recommendations. These documents typically cover certain technical areas in detail, such as connection of generation, switchgear ratings and supply quality planning limits.

There are other industry documents which are not implemented via the Distribution Code, but do have a material impact on distribution network users. These are listed in Annex 2 of the Distribution Code.

Standards and other documents referenced in Annex 1 and Annex 2 of the Distribution Code are available for free and can be downloaded at the following link:

Click here for Annex 1 and Annex 2 documents

Standard Governance Procedure

DNOs or Users may bring proposals for modifications to Annex 1 Standards and Annex 2 Standards for consideration by the DCRP Panel. DNOs and Users bringing forward proposals for modifications to Annex 1 Standards and Annex 2 Standards shall set out in general terms the aims of their proposal and the likely impact, including costs.

Further information on how to submit a modification can be found here.

Useful Links

Association for Decentralised Energy (formerly the Combined Heat & Power Association)
www.theade.co.uk

The Association of Manufacturers and suppliers of Power Systems and ancillary equipment
www.amps.org.uk/

Association of Meter Operators
www.meteroperators.org.uk

British Electrotechnical and Allied Manufacturers Association
www.beama.org.uk/

Department for Energy Security and Net Zero

www.gov.uk

Energy UK
www.energy-uk.org.uk

Major Energy Users’ Council
www.meuc.co.uk

Meter Operation Code of Practice Agreement (MOCOPA)
www.mocopa.org.uk

Microgeneration Certification Scheme
https://mcscertified.com/

National Grid
www.nationalgrid.com

National Grid
The Grid Code

Ofgem
www.ofgem.gov.uk

Renewable Energy Association
www.r-e-a.net

Renewable UK
www.renewableuk.com

Solar Trade Association
www.solar-trade.org.uk

Sustainable Energy Association (formerly Mircropower Council)
www.sustainableenergyassociation.com