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

Elexon is the Code Administrator for the Balancing and Settlement Code.

Modification reference number  Modification title  Lead team  Final modification report received  Expected date of decision   Ofgem expect to conduct an IA or consultation 
P487  Incentive of BSC Supplier Parties to meet the M15 MHHS Milestone  Consumer Protection and Retail Market 

17 June 2025 

 

28 August 2025  No 
P488  Aligning the BM Unit Rules for EII Assets in the BSC 

Distribution Charging and Non-domestic Retail 

 

2 July 2025 

 

8 August 2025  No 

Connection and Use of System Code (CUSC)

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

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

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  30 September 2025  No 

CMP315 

 

TNUoS: Review of the expansion constant and the elements of the transmission system charged for  Systems and Networks  7 February 2024  TBC  Yes 

CMP375 

 

Enduring Expansion Constant & Expansion Factor Review  Systems and Networks  7 February 2024  TBC  Yes 

CMP330 

 

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

CMP374 

 

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

CMP418 

 

Refine the allocation of Dynamic Reactive Compensation Equipment (DRCE) costs at OFTO transfer  Transmission Charging  12 March 2025  31 July 2025  No 

CMP450 

 

Introducing the definition of Dynamic Reactive Compensation Equipment (DRCE) in the CUSC  Transmission Charging  15 May 2025  31 July 2025  No 

Distribution Code (DC)

The Energy Networks Association is the body 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 the body responsible for the Distribution and Use of System Agreement

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

DCP446 

 

Emergency Disconnections  Distribution and Residual Charging  17 April 2025  3 September 2025  No 

DCP412 

 

Discounts from TCR charges for ‘peaky’ final demand customers  Distribution and Residual Charging  19 March 2025  TBC  No 
DCP437  To Shorten the DUoS Pricing Notice Periods 

Distribution Residual Charging 

 

16 June 2025  28 August 2025  No 
DCP440  Consuming 'De-energised' sites  Retail Market Operations  16 June 2025  22 August 2025  No 

Grid Code (GC)

NESO is the body responsible for the Grid Code

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

GC0166 

 

Introducing new Balancing Mechanism Parameters for Limited Duration Assets 

ESO Regulation 

 

08 July 2025  31 October 2025  No 

Independent Gas Transporters Uniform Network Code (IGT UNC)

The Independent Gas Transporters’ (IGT) Uniform Network Code (UNC) is the body responsible for the Independent Gas Transporters Uniform Network Code

There are no modifications to the IGT UNC with us for decision this month. 

Retail Energy Code (REC)

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

Modification reference number  Modification title  Lead team  Final modification report received  Expected date of decision  Ofgem expect to conduct an IA or consultation 
R0241 

MHHS Incremental Changes for go live 

 

Consumer Protection and Retail Market  16 July 2025  7 August 2025  No 

Smart Energy Code (SEC)

The Smart Energy Code Company houses the Smart Energy Code Administrator and Secretariat. SECCo is the body responsible for the Smart Energy Code

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

SEC MP286 

 

Establishment of the Privacy Sub-Committee into the SEC  Industry Codes  22 May 2025  5 August 2025  No 

Security and Quality of Supply Standard (SQSS)

NESO is the body responsible for the Security and Quality of Supply Standard

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

System Operator Transmission Owner Code (STC)

NESO is the body responsible for the System Operator - Transmission Owner Code

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

CM078 

 

STC change for CUSC Modification CMP328 - Connection Trigger Distribution Impact Assessment  Energy Systems Design and Development  7 June 2022  TBC   No 

Uniform Network Code (UNC)

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

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

D0001 

 

Hydrogen Blending: An NTS Transportation and Power Station Consumption Demonstration  Gas Systems and Operations  21 February 2025  TBC  No 

UNC0900 

 

Amendment to the Gas Quality NTS Entry Specification at Biomethane System Entry Points  Gas Systems and Operations  22 April 2025  TBC  No 
UNC0887  Facilitating Bi-Directional Connections Between IGT Pipelines and the NTS 

Gas Systems and Operations 

 

20 June 2025  19 August 2025  No 
UNC0886V  Amend the Code Cut-Off Date to a Rolling Period | Joint Office of Gas Transporters - Gas Governance  Retail Market Operations  22 July 2025  22 August 2025  No 
UNC0896  Reducing the current Code Cut-Off Date (Line in the Sand) from 3 to 4 years to 2 to 3 years | Joint Office of Gas Transporters - Gas Governance  Retail Market Operations  22 July 2025  22 August 2025  No