Half-hourly settlement deadline pushed back by more than a year

Ofgem has pushed back the primary completion deadline for the market-wide half-hourly settlement programme by more than a year from October 2025 to December 2026.

The regulator has also approved an alternative deadline of May 2027, meaning the completion of the programme could actually be delayed by up 19 months.

The decision comes after the programme managers warned that the prior transitional timeline has been viewed as “unrealistic and unachievable” since mid-2022 and “lacks widespread buy-in” among industry participants.

In a proposed change request, the managers explained that: “Challenging industry conditions, particularly in the light of the energy crisis in 2022, have impacted the market and the pace at which the programme has been able to move forward since the original timetable was set out.”

The transitional timeline was adopted in April 2021 when Ofgem finally gave the full go-ahead to the market-wide half-hourly settlement programme. The decision had already been delayed three times and was originally due to take place in the first half of 2018.

In August 2021, Ofgem decided that the transitional timeline should be reviewed once the detailed design architecture for the programme had been finalised. After completing its review, the Programme Management Office proposed a series of changes to key milestones for the programme at the beginning of April, which have now been accepted by the regulator.

The changes:

• Code drafting (milestone M6) – The deadline for baselining the necessary modifications to several industry codes has been delayed by 16 months from July 2023 to August 2024.
• Qualification (milestone M14) – The deadline for suppliers to qualify for the new settlement arrangements and be able to accept Meter Point Administration Numbers (MPANs) under the new Target Operating Model has been delayed by 13 months from February 2025 to March 2026. Suppliers that fail to meet this deadline will be banned from taking on new customers.
• Migration (milestones M11 and M15) – The deadline for starting the migration of MPANs to the new half-hourly settlement arrangements (M11) has been delayed by 6 months from October 2024, whilst the deadline for completing the migration (M15) has been delated by 12 months from October 2025 to October 2026. Taken together, this means the window for migration has also been extended by 6 months.
• Settlement timetable (milestones M16 and M16*) – The deadline for moving over to a new shorter and more efficient settlement timetable (M16) has been delayed by 13 months from November 2025 to December 2026. A new alternative deadline (M16*) set for May 2027 has also been introduced to provide an additional six-month range. This means the move to the new settlement timetable, which will mark the completion of the programme, could be delayed by up to 19 months.

Explaining its decision, Ofgem said that it “always recognised that the original plan, based on a high-level design, would need to be thoroughly reviewed once the detailed design had been baselined.

“Given that it took much longer than expected to finalise the detailed design, it is not surprising that the revised plan proposed to move several Level 1 milestones by three months or more,” the regulator added. “We are, however, satisfied that the revised plan represents the fastest realistically achievable timetable for industry.”

Ofgem said although the decision will increase industry implementation costs and delay the realisation of benefits, “this will have only a marginal effect” on the net benefits of the programme which are “orders of magnitude greater than the variations likely to be caused by this delay”.

“That said, MHHS remains a high priority for Ofgem and government as a means of enabling the lowest cost decarbonisation of the energy sector,” the regulator concluded. “Indeed, the persistence of historically high energy prices makes it all the more important to adhere to the revised plan and so deliver MHHS at the earliest practicable time.”

Ofgem said the revised timeline for the programme will be published by 30 June at the latest.