Industry codes and standards

About industry codes

Industry codes underpin the electricity and gas wholesale and retail markets. Licensees are required to maintain, become party to, or comply with the industry codes in accordance with the conditions of their licence.

Industry code modifications

All open modifications to the codes are listed in the Central Modifications Register. The code administrators update this register every month. 

We publish our own industry code decisions and notices

Expected decision dates

The expected decision date is the date we plan to publish our decision on a proposed code modification. 

The expected decision date is an indicator only. These dates may change due to developments in a particular modification proposal or other changes in priorities. 

These tables are updated every month to reflect any expected decision date changes.

Balancing and Settlement Code (BSC)

Elexon is the code administrator for the Balancing and Settlement Code.

Modification reference number  Modification Title  Lead team  Final modification report received  Expected decision date Ofgem expect to conduct an IA or consultation 
P444  Compensation for Suppliers and Virtual Lead Parties for Virtual Lead Party actions in the Balancing Mechanism  Wholesale Markets  11 October 2024  4 April 2025  No 

Connection and Use of System Code (CUSC)

The National Energy System Operator (NESO) is responsible for the Connection and Use of System Code.

Modification reference number Modification title Lead team Final modification report received Expected decision date  Ofgem expect to conduct an IA or consultation

CMP403 

 

Introducing Competitively Appointed Transmission Owners & 

Transmission Service Providers (Section 14) 

Onshore Networks  11 June 2024  By end of Mar 2025  No 

CMP404 

 

Introducing Competitively Appointed Transmission Owners & 

Transmission Service Providers (Section 11) 

Onshore Networks  11 June 2024  By end of Mar 2025  No 

CMP436 

 

Update CUSC arrangements to replace the Electricity Arbitration Association (EAA) with the London Court of International Arbitration (LCIA) (Non-Charging)  Industry Codes  07 Aug 2024  By end of Mar 2025  No 

CMP437 

 

Update CUSC arrangements to replace the Electricity Arbitration Association (EAA) with the London Court of International Arbitration (LCIA) (Charging)  Industry Codes  07 Aug 2024  By end of Mar 2025  No 

CMP443 

 

CMP443 - Removing references to “Fax” or “Facsimile” within the CUSC   Engineering Systems Design and Development  12 Feb 2025  By end of Mar 2025  No 

CMP441 

 

Reducing the credit risk of supplying non-embedded hydrogen Electrolysers  Distribution and Residual Charging  20 Dec 2024  18 Apr 2025  No 

CMP315 

 

TNUoS: Review of the expansion constant and the elements of the transmission system charged for  Systems and Networks  07 Feb 2024  TBC  Yes 

CMP375 

 

Enduring Expansion Constant & Expansion Factor Review  Systems and Networks  07 Feb 2024  TBC  Yes 

CMP330 

 

Allowing new Transmission Connected parties to build Connection Assets greater than 2km in length  Systems and Networks  10 Aug 2023  TBC   No 

CMP374 

 

Extending contestability for Transmission Connections  Systems and Networks  10 Aug 2023  TBC   No 

CMP397 

 

Consequential changes required to CUSC Exhibits B and D to reflect CMP316 (Co-Located Generation Sites)  Energy Systems Management and Security  12 June 2024  TBC  No 

Distribution Code (DC)

The Energy Networks Association is responsible for the Distribution Code.

There are no modifications to the Distribution Code with us for decision this month. 

Distribution Connection and Use of System Code (DCUSA)

Electralink is responsible for the Distribution and Use of System Agreement.

Modification reference number Modification title Lead team Final modification report received Expected decision date Ofgem expect to conduct an IA or consultation
DCP440  Consuming 'De-energised' sites  Retail Pricing and Systems  17 January 2025  11 March 2025  No 
DCP439  Backdating Tariff Changes  Distribution and Residual Charging  18 September 2024  14 March 2025  No 

Grid Code (GC)

The National Energy System Operator (NESO) is responsible for the Grid Code.

Modification reference number Modification title Lead team Final modification report received Expected decision date Ofgem expect to conduct an IA or consultation
GC0175  GC0175: Removing references to 'Fax' or 'Facsimile' within the Grid Code  Engineering Systems Design and Development  4 February 2025  By end of March 2025  No 
GC0159  Introducing Competitively Appointed Transmission Owners  Onshore Networks  31 December 2024  By end of March 2025  No 
GC0172  Replacing References to Electricity Supply Industry Arbitration Association  Industry Codes  7 August 2024  By end of March 2025  No 
GC0117  Improving transparency and consistency of access arrangements across GB by the creation of a pan-GB commonality of PGM requirements  Networks and Systems  14 May 2024  7 May 2025  Yes 

Retail Energy Code (REC)

The Retail Energy Code Company limited is responsible for the Retail Energy Code

Modification reference number Modification title Lead team Final modification report received Expected decision date Ofgem expect to conduct an IA or consultation
R0173   Improvements to the Theft Detection Incentive Scheme  Retail Pricing and Systems  4 December 2024  3 March 2025   No 
R0137A   Introducing Third Party Intermediary (energy broker) assurance and accreditation  Consumer Protection and Retail Markets  4 December 2024  TBC  No 

Smart Energy Code (SEC)

The Smart Energy Code Company houses the Smart Energy Code administrator and secretariat. SECCo is responsible for the Smart Energy Code

Modification reference number  Modification title  Lead team  Final modification report received  Expected decision date  Ofgem expect to conduct an IA or consultation 
SEC MP271 Sub-Committee seats for Other Users, Meter Data Retrievers and Registered Supplier Agents  Industry Codes  27 January 2025  11 April 2025  No 

System Operator Transmission Owner Code (STC)

The National Energy System Operator (NESO) is responsible for the System Operator Transmission Owner Code

Modification reference number Modification title Lead team Final modification report received Expected decision date Ofgem expect to conduct an IA or consultation
CM0086   Introducing Competitively Appointed Transmission Owners and Transmission Service Providers  Onshore Networks  11 March 2024  By end of March 2025  No 
CM0087   Introducing Connections Process to facilitate Competitively Appointed Transmission Owners  Onshore Networks  11 March 2024  By end of March 2025  No 
CM0098   Updating STC Arrangements to replacing the Electricity Arbitration Association with the London Court of International Arbitration  Industry Codes  7 August 2024  By end of March 2025  No 
CM0078  STC change for CUSC Modification CMP328 - Connection Trigger Distribution Impact Assessment  Energy Systems Design and Development  7 June 2022  TBC   No 

Independent Gas Transporters Uniform Network Code (IGT UNC)

Independent Gas Transporters Uniform Network Code (IGT UNC) is the code administrator for the Independent Gas Transporters Uniform Network Code.

There are no modifications to the Independent Gas Transporters Uniform Network Code with us for decision this month.

Uniform Network Code (UNC)

The Joint Office of Gas Transporters is responsible for the Uniform Network Code

Modification reference number Modification title Lead team Final modification report received Expected decision date Ofgem expect to conduct an IA or consultation
UNC860   Clarify impact of exit capacity holdings on offtake rights   Gas Systems and Operations  20 September 2024  28 February 2025  No 
UNC870  Amendments to Wobbe Index and Calorific Value Lower Limits at NTS System Entry Points   Gas Systems and Operations  17 January 2025  21 March 2025  No 
D0001  Hydrogen Blending: An NTS Transportation and Power Station Consumption Demonstration  Gas Systems and Operations  21 February 2025  TBC  No