Change Consultations
This page lists all Change Consultations which are opened when we need to obtain feedback from the industry on potential Modifications, Change Proposals and Issues. The page also includes Change Consultations which have ceased to be active as they have reached their closed date.
Please note that we publish Change Proposal Consultations (CPCs) when communicating consultations for Change Proposals. Change Proposal Consultations highlight change information and Impact Assessment responses.
List of Change Consultations
P486 ‘Aligning BSC Terminology with the Terminology Introduced by P478’ Report Phase Consultation
This Modification proposes to clarify the meaning of the term Half-Hourly Metering System(s), a new definition used in the Modification P478 ‘Implementation of MHHS Arrangements’ Legal Text. This will clarify where the new usage is equivalent to the current definition and where it is distinct, to avoid ambiguity or unintended consequences throughout the BSC.
Request for Information: ISD data accuracy prior to MHHS Milestone M10
In order to finalise the preparations for the Market-Wide Half-Hourly Settlement (MHHS) Milestone M10, scheduled for September 2025, Elexon is issuing this Request for Information (RFI) to gather further insights and confirm the accuracy of the collated ISD data by the collaborative efforts of MHHS, Elexon, and LDSOs.
The purpose of this RFI is to identify any potential discrepancies and ensure that all required adjustments are made prior to the ISD data migration.
Elexon will collate all feedback and respond to changes where required. The changes will be presented at the Supplier Volume Allocation Group (SVG) committee for approval in readiness for MHHSP ISD Data Migration
P483 Assessment Procedure Consultation
This Modification seeks to address this issue by removing the Half-Hourly settlement requirement for associated Boundary Point Metering Systems. Doing so will expand access to flexibility markets for domestic consumers, support equitable participation in energy services, and reduce the dependency on Market-wide Half-Hourly Settlement (MHHS) for consumer inclusion. This change is expected to enable flexible asset participation and support energy system goals such as Clean Power 2030.
Consultation on P485 Stabilise TLFs for BSC Year 2025/26 at 2024/25 levels
This Urgent Modification proposes that, until the BSC Panel’s determination that 2025/26’s Transmission Loss Factors (TLFs) reflect expected changes in variable losses due to marginal demand or generation changes as anticipated when BSC Modification P350 was approved, TLFs from the 2024–25 BSC Year will apply to the 2025-26 BSC Year from the P485 Implementation Date.
The Panel must decide what TLF values, the ‘corrected values’, to apply. The Panel are consulting on two solution options. Under the Proposed, the ‘corrected values’ will be applied from 1 April 2025. Under the Alternative solution, the ‘corrected values’ will apply from the BSC Season following the Panel determination.
Consultation on P484 Amending BSC Metering Obligations for CfD Assets
This Modification aims to align BSC rules with evolving CfD arrangements by introducing greater flexibility in how assets are registered within BM Units. By simplifying administrative processes and supporting efficient energy management, this change helps market participants optimise their operations while ensuring continued compliance with the BSC. Additionally, it reflects ongoing developments in Government policy, allowing for a more adaptable and streamlined approach to CfD asset management.
Urgent Modification Consultation for P482: Enable flexible splitting of BSC Agent services and establishing contracts for MHHS Delivery
To support the transition to Market-Wide Half-Hourly Settlement (MHHS), Elexon must sign BSC Agent contracts for the operation of new services. This Modification seeks to allow more flexibility in the requirements for procurement of BSC Agents for the SVAA services at MHHS go-live. It will provide the option of having these new MHHS systems operated by the service providers who developed them, while the currently appointed Supplier Volume Allocation Agent (SVAA) continues to operate legacy processes
CP1592 Implementation Phase Consultation to Upgrade of NHHDA and EAC/AA systems
The current versions of NHHDA (Non Half Hourly Data Aggregation) and EAC/AA (Estimation of Annual Consumption/Annualised Advance) system applications that Elexon provides to Party Agents run on Oracle 12c, for which Oracle Corporation withdrew application support in 2022.
This CP proposes to upgrade EAC/AA and NHHDA to the latest available version of Oracle 19.21. Where possible, it leverages cost savings by aligning with Elexon’s planned update to other BSC central systems
P480 Report Phase Consultation Publication of regional demand forecast data to fulfil ESRS Reporting requirements
P480 seeks to facilitate the Electricity System Restoration Standard (ESRS) requirements to publish the day-ahead peak demand forecast for each restoration region and the demand restored in each restoration region published hourly during a System Restoration on BMRS (Elexon’s Insights Solution Platform). P480 is a consequential Modification to GC0156 ‘Facilitating the Implementation of the Electricity System Restoration Standard’.
This Proposed Solution is to make changes to BSC system and BSC Section Q ‘Balancing Mechanism Activities’ and Code Subsidiary Documents to implement these provisions outlined in GC0156.
P475 Implementation Consultation on BM Units production / consumption flags
The purpose of this implementation consultation is to seek feedback from industry participants on the proposal to bring forward the Implementation Date of P475. By gathering views on the revised timeline, the consultation allows stakeholders to assess and respond to the impact of an earlier delivery of the Modification.
Elexon has identified an opportunity to adjust the timeline, allowing for the earlier delivery of the Modification’s benefits. This feedback will help the BSC Panel make an informed recommendation to the Authority regarding the updated implementation date, ensuring that both market and participant needs are considered.
Second Implementation Consultation for P466: BSC Section N Modernisation
The Authority have sent us a Direction triggering Paragraph 2.11.18 of BSC Section F, this sets out that Ofgem may direct the BSC Panel to consult on a revised proposed Implementation Date for a Modification. This is due to the Authority considering that the proposed Implementation Date and the previously revised Implementation Date is, or may no longer be, appropriate or might otherwise prevent Ofgem from making a decision.