On 7 October 2026, Britain's grid operator retired a market it had spent three years proving worked.
The Local Constraint Market ran on Piclo's cloud platform, buying distribution-connected flexibility at the B6 boundary between Scotland and England. Its first trades cleared in May 2023. It has now been folded into the Demand Flexibility Service — the national merit-order tool that began as a winter emergency measure in 2022/23 and by March 2026 counted 2.46 million registered businesses and consumers.
Consolidating a bespoke locational market into one national service should make flexibility easier to sell. On the volume NESO actually publishes, it is also happening at a scale that has not yet moved.
The market that was retired
Piclo built the LCM platform in three months after the partnership was announced in December 2022. By the operator's own account to a UK Parliament inquiry, it was the first time a national electricity control room had used cloud software end to end to procure and dispatch flexibility. Eligible assets had to sit in Scotland, be distribution-connected, and fall outside both the Balancing Mechanism and the Access and Forward-Location Measures. There was no minimum volume floor. Bidding ran day-ahead and intra-day, and providers were paid only on energy actually delivered, with no penalty for under-delivery.
That is a well-drawn contract for small assets. It is also, precisely, the shape a 0.1MW eligibility floor and a national merit-order queue can absorb without much redesign.
Three years of evidence, folded into one service
On 27 November 2024 the DFS became a year-round in-merit margin tool. On 30 January 2026 NESO submitted a proposal to amend the Article 18 terms and conditions; Ofgem approved it on 25 March. On 9 April the service added bi-directional flexibility, zonal procurement, Primacy and a self-nominated baseline option, while cutting the unit threshold from 1MW to 0.1MW. On 7 October it absorbed constraint management actions, and NESO stopped buying them through the Local Constraint Market.
Five changes in twenty-two months. Nearly all of them widened access. Very few of them added locational price signal.
Access was the stated reason, and it was a real barrier. NESO's own participation guidance calls the old one-megawatt floor "widely cited as a constraint to flexibility participation."
DFS will provide a larger and more accessible route to market for flexibility providers, increase competition, and deliver greater value for consumers.— NESO, Local Constraint Market transition notice
The access case is settled. The signal question is not.
Registered with the DFS
Businesses and consumers signed up to the Demand Flexibility Service as of March 2026 · NESO, March 2026
Delivered in-merit
Energy delivered by the DFS since it became a year-round margin tool · NESO, March 2026
Cut from 1MW in April
Great Britain is now procured in 12 zones mapped to the most heavily loaded transmission boundaries · NESO, August 2026
The threshold mattered more than the merger
Great Britain is now divided into 12 procurement zones, mapped to the most heavily loaded transmission boundaries. A DFS unit can register at 0.1MW and be built from aggregated assets inside a single zone. Providers can nominate their own baseline instead of accepting NESO's ten-working-day average.
For an aggregator, that is the commercial case. Before April, a portfolio of domestic batteries or EV chargers had to clear a megawatt to be worth registering at all. Now a few hundred kilowatts of flexible load qualifies.
| Parameter | Local Constraint Market | Demand Flexibility Service |
|---|---|---|
| Price basis | Locational, at the constrained boundary | ✗ National merit-order clearing |
| Asset eligibility | ✔ Distribution-connected, Scotland side | ◐ Any zone, half-hourly settled |
| Minimum volume | ✔ No floor | ✔ 0.1MW per unit |
| Aggregation | ✗ Platform-level, per submission | ✔ Aggregated assets within a zone |
| Service actions | Turn down, turn up | ✔ Turn down, turn up, margin + constraint |
Compiled from NESO service documentation, current from 7 October 2026.
One April change is invisible in the headline figures and deserves more attention than it has got. For the first time, primacy arrangements were embedded directly into DFS procurement. Elexon, acting as the UK's flexibility market facilitator, built a Risk of Conflict reporting capability with the distribution network operators so they can flag, ahead of an event, the moments where national procurement would create a local network problem.
Read generously, that is mature whole-system coordination. Read precisely, it is an admission that the national service and the local network do not reach the same answer — and that the system operator is now funding a machine to reconcile them before every event.
National requirement, zonal caps
The mechanic that should decide who builds software against this market sits in a different paragraph of the same guidance document.
The DFS service requirement is still calculated nationally, from the overall energy margin. Zonal caps only limit how much of that requirement NESO will accept in any one zone, and every service requirement carries a stated maximum volume per zone.
So a provider sitting in a congested zone does not receive a different price. It receives a smaller slice of one national price, conditioned on where the asset physically is. The scarcity signal the Local Constraint Market produced — congestion at B6, priced at B6 — has been replaced by a geographic allocation rule layered on top of a flat national clearing.
Workable, and less information than before. For anyone building forecasting or orchestration software, that inversion matters: a model that predicts the national margin earns the baseline price and stops there. Predicting where the cap will bind is a different problem, a harder one, and a much less specified one.
As we wrote in October about NOX Energy's €3M raise to trade household heat pumps like a currency, aggregation was already turning a fixed domestic load into a tradable position. The mechanism is the same. What changes here is the market underneath it.
The scale is the part worth stating plainly. By March 2026 the DFS had delivered over 12,000 MWh since becoming an in-merit tool in November 2024. That is a small number for a national balancing service, and it is the only volume figure NESO publishes today. This consolidation is happening on top of it — which makes the next two years of DFS data the real test of whether access and signal can be had together.
Octopus Energy wants the opposite kind of consolidation
The industry's answer to the proposal did not say stop. It said go further.
Utility Week reported in August 2026 that Octopus Energy responded to the proposed LCM merger by arguing for wider consolidation across flexibility markets, flagging that value is fragmented across numerous overlapping markets that create operational complexity and hinder efficiency. The same month, NESO separately decided to keep distributed energy resources out of reactive power markets.
Put together, that is one argument rather than two: Britain's flexibility problem is no longer too few markets. It is that a home battery or a heat pump has to discover, register for and settle against each of them separately.
Consolidation is the right answer to that. It is a blunt answer to the other question — where in the network the value actually sits — and NESO has bet that a flat national price plus zonal caps plus a priority-conflict flag is enough to find it.
DFS volume after the 7 October constraint transition, against the 12,000 MWh in-merit baseline
Whether NESO publishes zonal clearing prices, or only zonal caps
Piclo's role once the LCM contract ends — and whether the platform capability survives the merger
The first DFS Market Information Report covering constraint actions
What the next twelve months decide
Probability: 60% — the 0.1MW floor, zonal aggregation and self-nominated baselines all widened the funnel, and constraint procurement adds a new reason to call an event.
✅ Arguments for
Constraint actions give distribution-connected assets a reason to register that the national margin tool never gave them.
Criteria for confirmation: the DFS Market Information Report shows constraint actions clearing volume in more than two of the 12 zones.
❌ Arguments against
Constraint management is inherently local. Running it through a national merit-order process may simply relocate the queue rather than shorten it.
Criteria for refutation: NESO reopens a locational price signal, or the DNO layer takes constraint procurement back and the DFS constraint capability goes quiet.
🟢 Optimistic scenario (35%)
Consequence: a domestic battery or heat pump becomes a balance-sheet asset for the first time.
🟡 Base scenario (45%)
Consequence: a larger, cheaper, blunter market.
🔴 Pessimistic scenario (20%)
Consequence: consolidation removes a working locational market and buys very little.