P434 ‘Half Hourly Settlement for UMS Metering Systems’
Formal title: Mandate to Half Hourly Settle the Non-Half Hourly Unmetered Supplies Metering Systems
This Modification will require a period of mandatory Change of Measurement Class (CoMC) activity for all Non-Half Hourly (NHH) Unmetered Supplies (UMS) Metering Systems to complete before the Market Wide Half Hourly Settlement (MHHS) migration to the Target Operating Model (Milestone 11 (M11) in the MHHS Timetable). At the time of writing, this would need to complete by October 2024. It will also require all new UMS connections to be settled Half Hourly (HH) from 12 months prior to M11, currently October 2023.
If the transition for NHH UMS Metering Systems is not brought forward, combined with the workload from other MHHS activities, It will significantly increase the risk that there will be insufficient time for Customers, Suppliers and UMSOs to address any issues that may arise with the transition to the MHHS Target Operating Model.