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Code change calendar

Check the expected outcomes of energy code modification proposals.

We approve or reject energy code modifications. The calendar is updated every month, dates of expected outcomes may change.

Find out more about each modification, including a summary, on the central register.

Check the central modifications register.

If you are affected by an energy code, you can propose a change to the body administering that code.

Contact a code administrator

Energy code Number and title Lead team Ofgem received Expect an outcome by Ofgem consultation?
Retail energy code R0241: MHHS (market-wide half-hourly settlement) incremental changes for go live Consumer protection and retail market 16 July 2025 7 August 2025 No
Smart energy code SEC MP286: Establishment of the privacy sub committee into the SEC Industry codes 22 May 2025 5 August 2025 No
Balancing and settlement code P487: Incentive of BSC supplier parties to meet the M15 MHHS milestone Consumer protection and retail market 17 June 2025 28 August 2025 No
Balancing and settlement code P488: Aligning the BM (balancing mechanism) unit rules for EII (electricity-intensive industry) assets in the BSC Distribution charging and non-domestic retail 2 July 2025 8 August 2025 No
Connection and use of system code 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
Connection and use of system code CMP315: TNUoS (transmission network use of system) review of the expansion constant and the elements of the transmission system charged for Systems and networks 7 February 2024 To be confirmed Yes
Connection and use of system code CMP375: Enduring expansion constant and expansion factor review Systems and networks 7 February 2024 To be confirmed Yes
Connection and use of system code CMP330: Allowing new transmission connected parties to build connection assets together Systems and networks 10 August 2023 To be confirmed Yes
Connection and use of system code CMP374: Extending contestability for transmission connections Systems and networks 10 August 2023 To be confirmed No
Connection and use of system code CMP418: Refine the allocation of dynamic reactive compensation equipment costs at OFTO transfer Transmission charging 12 March 2025 31 July 2025 No
Connection and use of system code CMP450: Introducing the definition of dynamic reactive compensation equipment in the CUSC Transmission charging 15 May 2025 31 July 2025 No
Distribution connection and use of system code DCP446: Emergency disconnections Distribution and residual charging 17 April 2025 3 September 2025  
Distribution connection and use of system code DCP412: Discounts from TCR (targeted charging review) charges for 'peaky' final demand customers Distribution and Residual Charging  19 March 2025  To be confirmed No 
Distribution connection and use of system code DCP437: To shorten the DUoS (distribution use of system) pricing notice periods 

Distribution residual charging 

 

16 June 2025  28 August 2025  No 
Distribution connection and use of system code DCP440: Consuming 'de-energised' sites  Retail market operations  16 June 2025  22 August 2025  No 
Uniform network code D0001: Hydrogen blending. An NTS (national transmission system) transportation and power station consumption demonstration  Gas systems and operations  21 February 2025  To be confirmed No 
Uniform network code UNC0900: Amendment to the gas quality NTS entry specification at biomethane system entry points  Gas Systems and Operations  22 April 2025  To be confirmed No 
Uniform network code UNC0887: Facilitating bi-directional connections between IGT (independent gas transporter) pipelines and the NTS 

Gas Systems and Operations 

 

20 June 2025  19 August 2025  No 
Uniform network code 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 
Grid code GC0166: Introducing new balancing mechanism parameters for limited duration assets 

ESO regulation 

 

08 July 2025  31 October 2025  No 
System operator transmission owner code CM078: STC change for CUSC modification CMP328 - connection trigger distribution impact assessment  Energy systems design and development  7 June 2022  To be confirmed  No