Ofgem's call for input on the technical approach to adapting the energy price cap for Market Wide Half-Hourly Settlement (MHHS) closed on 6 May 20261. The regulator opened the consultation on 25 March 2026 and asked for responses by 5 May 2026, by email to priceprotectionpolicy@ofgem.gov.uk1. The page now carries the status "Closed"1.
The call for input set out Ofgem's initial thinking on how the energy price cap may need to develop to accommodate MHHS, which the regulator says "will result in changes in how suppliers are settled when purchasing electricity to match their customers' demand"1. Ofgem stated its purpose directly:
"We are seeking views on how to adapt the wholesale allowance of the energy price cap to accommodate Market Wide Half-Hourly Settlement (MHHS)."
The document set out three areas of thinking: setting an electricity wholesale allowance that allows the cap to track and reflect the efficient costs of serving cap customers over time; whether and how to account for differences in costs to serve customers across customer groups and suppliers; and developing the cap for customers who want to change how and when they use electricity, for example time of use pricing where the price varies by when electricity is used1.
To adapt the cap, Ofgem said it considers it needs to update how it sets the cap level for single-rate customers, who pay the same price regardless of when they use electricity; design at least one time of use cap variant, for those who pay different prices depending on when they use electricity; and consider whether further risk mitigations are required to address differences in costs to serve suppliers' customer bases1.
Ofgem invited views from energy suppliers, energy industry bodies, network companies, consumer groups, charities and consumers1. The call for input was filed under the topic "Energy pricing rules" and the subtopic "Energy price cap"1.
Why it matters for households
The price cap sets the default tariff level for millions of households, so any change to how its wholesale allowance is calculated feeds through to the unit rates and standing charges on those tariffs. The energy bills and the price cap guide explains how the cap works in practice.
The MHHS element concerns how suppliers are settled for the electricity they buy to match customer demand. If settlement moves to half-hourly periods, the costs suppliers face for serving customers at different times of day may diverge more sharply. Ofgem's questions about "differences in costs to serve these customers across customer groups and suppliers" go to whether some households could end up carrying costs that reflect when they use power, rather than a single averaged rate1.
The proposal to design at least one time of use cap variant is the part most likely to be visible to households. A time of use cap would apply to customers on tariffs where the price varies depending on when electricity is used, rather than the single-rate structure most default tariffs use today1. That has a bearing on energy independence at home, because shifting consumption to cheaper periods is one of the few levers a household controls directly, and the cap design determines whether that lever exists on a protected tariff.
No decision has been announced. The call for input was a consultation stage, and the page records only that it has closed1. How the responses will be used, and whether a further consultation will follow, has not been reported.
What happens next
Ofgem has not published a timetable beyond the close of the call for input on 6 May 20261. No date for a decision, a further consultation or draft licence changes appears on the page1. The energy consultations guide sets out how this stage fits into the wider process by which rules are proposed, decided and changed.