Ofgem has approved Retail Energy Code (REC) Change Proposal R0209, titled "Implementation of Market-wide Half-Hourly Settlement (MHHS) Arrangements". The regulator published its decision on 26 November 2024 as a code modification, listed under the topics of electricity supply and energy codes, and the subtopics of the retail energy code and market-wide half-hourly settlement1.
"We have approved Retail Energy Code (REC) Change Proposal (R0209) 'Implementation of Market-wide Half-Hourly Settlement (MHHS) Arrangements'."
The decision sits within the work of Ofgem on the retail energy code, the rulebook that governs how suppliers, meter operators and other parties interact in the domestic and non-domestic electricity retail market1. Market-wide half-hourly settlement is the programme that changes how electricity consumption and generation are measured and settled, moving from aggregated, less frequent readings to half-hourly data across the market1.
The published decision page carries the approval statement and links to the main document, an R0209 decision letter in PDF form1. Ofgem lists the publication type as a code modification and dates it 26 November 20241. No further detail on the mechanics of the change, the obligations it places on individual parties, or the costs involved appears on the published decision page1.
The decision page does not set out a timetable for the rollout of half-hourly settlement, nor does it state which parties must act first or by when. Those details have not been reported on the page. What the approval does establish is that the implementation arrangements for MHHS now form part of the approved retail energy code1.
Why it matters for households
Half-hourly settlement changes the basis on which electricity used in a home is measured and priced in the wholesale market. Instead of suppliers settling on the basis of profiled, estimated or less frequent consumption data, settlement moves to half-hourly readings, which is the level of detail smart meters already record. For a household, the practical link is between the meter in the property and the data that flows from it: the more precisely a home's consumption is measured, the more precisely it can be valued, and the more scope there is for time-of-use products that reward shifting demand away from peak periods.
That has a bearing on energy independence in the everyday sense: a household's ability to use its own generation, storage or flexible load to reduce what it buys at expensive times depends on settlement and metering arrangements that can recognise when electricity was used. The R0209 decision is one of the code steps that puts those arrangements in place. It does not, on the published page, change any household's tariff, meter or contract, and no consumer-facing obligations are set out there1.
What happens next
The decision letter linked from the publication is the main document supporting the approval1. No implementation dates, milestones or compliance deadlines are given on the published decision page, and none have been reported there1.