P487 Balancing and Settlement Code (BSC) proposed changes

Details of outcome

Ofgem has decided to approve BSC Modification P487. Implementation of the modification proposal will, on balance, better facilitate the achievement of the applicable objectives of the BSC.

Start date

The implementation date for BSC Modification P487 is the date on which the notified changes to the Market-wide Half-Hourly Settlement (MHHS) Migration Framework setting out the process for P487 are implemented, or 25 June 2026, whichever is earlier.

Code modification description

Under the MHHS programme, electricity Suppliers are required to complete the migration of their Meter Point Administration Numbers (MPANs) by the MHHS Milestone 15 (‘M15’) deadline of 7 May 2027. After this date, the legacy settlement systems can be turned off once the last settlement date with MPANs in the legacy arrangements has been reconciled.

On 7 April 2025, the Secretary of State for Energy Security and Net Zero and Ofgem’s Chief Executive Officer issued a joint letter to all MHHS Participants making clear that there should be no further delays to MHHS delivery. As a contribution towards this, Elexon developed P487. This provided that any failure by a Supplier to complete its MHHS migration by M15 would result in that Supplier being restricted from registering new customers until it had completed its MHHS migration. In August 2025, Ofgem sent back P487 for further development. In response, Elexon (MHHS Programme) revised the proposed BSC legal text to provide that the restriction on new registrations for a Supplier that had failed to complete MHHS migration by M15 would not come into effect if the MHHS Senior Responsible Owner had granted that Supplier an exemption. MHHS Programme also drafted revisions to the MHHS Migration Framework setting out how the exemptions and related appeals processes would work and guidance on the circumstances in which exemptions would and would not be likely to be issued. On 11 December 2025, the BSC Panel nevertheless agreed to recommend that Ofgem should reject the modification.

Ofgem received the Revised Final Modification Report on 15 December 2025. Since receiving it, we have conducted an assessment of the potential impact of the modification on competition and consumers. We have also considered the outcomes of the Programme Participant Information Request on ‘Troublesome MPANs’ that was issued by MHHS Programme on 16 February 2026. In light of all the information available to us, we consider that P487 will better facilitate BSC Applicable Objectives (c) and (d) and therefore we have decided to approve it. The draft proposals to revise the MHHS Migration Framework are subject to MHHS programme Change Request governance procedures rather than to the BSC modification process. We expect that MHHS Programme will now consult on them, substantially on the basis of the documentation that was provided to the BSC Panel in December 2025, as soon as possible.