Milestone 10 (M10) Programme Updates

M10 and M13 approved

At the Extraordinary Programme Steering Group (ePSG) meeting on Wednesday 24 September 2025, the Senior Responsible Owner (SRO) approved two key milestones: 

  • M10: Central systems ready to migrate Meter Point Administration Numbers (MPANs) 
  • M13: Load Shaping System (LSS) switched on 

This approval marks a significant step towards full Market-wide Half-Hourly Settlement (MHHS) implementation and follows the successful transition of Central Services and Licensed Distribution System Operators (LDSOs) in line with the M10/M11 Cutover Plan. 

The Programme will now progress through the governance choreography for the next milestones: 

  • M11 - Start of Migration for UMS/Advanced: Suppliers will begin migrating Unmetered Supply (UMS) and Advanced metering MPANs 
  • M12 – Start of Migration for Smart/Non-Smart: Suppliers will begin migrating Smart and Non-Smart MPANs

Recommendations on M11 and M12 will be provided by the Migration & Cutover Advisory Group (MCAG), followed by SRO approval at the Programme Steering Group (PSG). Dates for these October governance groups will be shared in due course. 

The Programme extends its thanks to the Systems Integration Testing (SIT) participants, Central Parties and Core Capability Providers, Code Bodies, Representatives for industry meetings, Ofgem Programme Sponsors for their ongoing support and engagement, and finally the MHHS Programme Lead Delivery Partner (LDP) Team and SRO Team in reaching this milestone. 

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Operating between M10 and M11 

During the period between M10 and M11, legacy settlement activity for all periods post-M10 will be undertaken on the newly re-platformed Volume Allocation Service (VAS) which the Programme will monitor closely as part of the readiness criteria for M11. 

 

Code changes (M8) published 

The Programme is also pleased to confirm that Milestone 8 (M8) the delivery of Code changes has been published by the Balancing & Settlement Company (BSC), Retail Energy Code Company (RECCo), and the Distribution Connection and Use of System Agreement (DCUSA).

This codification of the MHHS Target Operating Model (TOM) and Design establishes the legal baseline for the new MHHS arrangements. 

If you have any questions, please email the Programme Party Coordinator (PPC) team at PPC@mhhsprogramme.co.uk