What replaces ECO4 after December 2026?

There is no ECO5 and no successor supplier obligation. When the Energy Company Obligation 4 scheme closes on 31 December 2026, the arrangement that has obliged energy suppliers to fund insulation and heating measures for low income and vulnerable households since 27 July 2022 comes to an end, and nothing of the same kind replaces it¹. Ceredigion Council's guidance on the scheme states the position plainly: "The ECO4 scheme was due to end on March 31st 2026, with no subsequent ECO5 replacement."¹

What replaces it is a different model. The government's Warm Homes Plan aims to upgrade 5 million homes and reduce long-term costs, moving support from an obligation placed on suppliers towards grant funding delivered through new programmes, including the Warm Homes: Local Grant³. Alongside that, the Great British Insulation Scheme continues to deliver mostly single insulation measures, the Warm Home Discount has been confirmed for a new five-year period to 2030/31, and each nation runs its own schemes: the new Warm Homes Programme in Wales, Warmer Homes Scotland's successor arrangements, and the Warm Healthy Homes Fund in Northern Ireland³.

For a household that would have qualified under ECO4, the practical change is that the largest pot of supplier-funded, whole-house retrofit money, worth £4 billion across the scheme, stops at the end of 2026, and the routes that remain are grants with their own rules, discounts on bills, and nation-run programmes⁸. This page sets out what is confirmed, the key dates, why the end date moved, and what happens to work still in progress.

What is confirmed so far

The single most important fact for households planning work is a negative one: there is no ECO5. The supplier obligation model, in which obligated energy suppliers must fund measures or face penalties, ends with ECO4, and no replacement obligation of the same kind has been announced¹. Anyone searching for an "eco5 scheme" or an "eco4 successor 2027" will not find one, because the government's direction of travel is grant funding rather than supplier obligation.

What is confirmed in its place is the Warm Homes Plan, which the government's performance report describes as intended "to upgrade 5 million homes and reduce long-term costs"³. Within that plan sit the new grant programmes covered elsewhere on this site, including the Warm Homes: Local Grant and the Warm Homes: Social Housing Fund. The Boiler Upgrade Scheme also continues as the main grant for heat pumps and biomass, and the Great British Insulation Scheme runs alongside ECO4 delivering predominantly single measures to a wider range of households⁴.

Two things do not change on 31 December 2026. The Warm Home Discount, which reduces electricity bills for eligible households, has been confirmed for a new five-year scheme period from 2026/27 to 2030/31⁵. And the energy price cap continues to be set by Ofgem, which responded formally to the price cap aspects of the consultation on extending ECO4's end date¹¹. So the loss at the end of 2026 is specifically the supplier-funded retrofit scheme, not the wider framework of bill support.

For household energy independence, this matters in a particular way. ECO4 funded whole-house retrofits, meaning insulation, heating and renewable measures delivered together, which is the approach that most reduces a home's dependence on imported gas and on volatile bills¹². The schemes taking over mostly fund single measures or single technologies, so a household aiming for full independence will need to sequence applications across several programmes rather than receive one coordinated package.

ECO4 closes at the end of December: key dates

ECO4 commenced on 27 July 2022 and, following a nine-month extension, runs until 31 December 2026². The scheme is administered by Ofgem on behalf of the Gas and Electricity Markets Authority¹². Its obligation period is split into four phases, and the final phase, Phase 4, runs from 1 April 2025 to 31 December 2026¹².

The scheme is worth £4 billion in total, and its focus is whole-house retrofits for low income and vulnerable households⁸. That focus is what distinguishes it from the schemes that follow: ECO4 was designed so that a qualifying home could receive a package of measures, for example loft, wall and floor insulation together with a heating upgrade and solar PV, delivered as one project¹³.

One point of caution for households hoping to apply late in the scheme: some local routes have already stopped. East Herts Council states that "The scheme has now closed to new applications."¹⁴ The obligation period itself runs to 31 December 2026, but individual councils and delivery partners can close their ECO4 Flex referral routes earlier once their allocated funding is committed, so a household relying on a local route should check with that council directly rather than assume the national deadline applies locally.

Why the end date changed from March to December

ECO4 was designed to run from 27 July 2022 to 31 March 2026, and that remained the stated end date in the scheme's delivery guidance through 2025¹⁵. The government then consulted on extending the end date, and the consultation response confirmed that "ECO4 will be extended by 9 months to 31 December 2026"⁹.

The reasons given are practical rather than political. A Commons research briefing summarises the purpose of the extension: "ECO has been extended to 31 December 2026 to meet existing targets and remediate non-compliant installations."¹⁶ Two problems were being solved at once. First, suppliers were behind on their obligations, and a hard stop in March 2026 would have left targets unmet and households who had been assessed without completed work. Second, a significant number of installations, particularly solid wall insulation, had been carried out to a poor standard, and the extension created time to put them right¹⁷.

Ofgem engaged with the extension on its own terms, publishing a response to the price cap aspects of the consultation, because changes to the obligation affect the costs suppliers recover through bills¹¹. Separately, Ofgem had already consulted on and decided the administration of mid-scheme changes to ECO4 and the Great British Insulation Scheme, receiving responses from 9 suppliers, 5 installers and 4 from related industry bodies and consumers¹⁸. Those mid-scheme changes included the move to updated installation standards, covered below.

For households, the extension cuts both ways. It gives nine more months in which a home can receive measures under a scheme with no successor, which is a genuine gain for anyone whose application was in progress. But it also means the remediation of poor-quality work is happening inside the same window, so capacity at installers is split between new installations and corrections to old ones.

ECO4's phases: from launch as the successor to ECO3

ECO4 was designed as the successor to ECO3, focusing on supporting low-income, vulnerable and fuel poor households through delivering energy efficiency measures¹⁹. The design consultation for the scheme settled an important rule that still shapes applications: "carry-under will not be implemented", meaning suppliers could not bank unused obligation from one scheme into the next²⁰.

The obligation period is split into four phases, each with its own supplier notification deadlines for domestic customer numbers¹².

The phases matter to households mainly through delivery capacity. Suppliers notify Ofgem of their customer numbers by a deadline early in each phase, which sets the size of each supplier's obligation for that phase, and funding availability within a phase can run out before the phase itself ends¹². The supplier notification deadlines were 17 August 2022 for Phase 1, 1 February 2023 for Phase 2, 1 February 2024 for Phase 3 and 1 February 2025 for Phase 4¹².

There was also an early delivery window: measures completed between 1 April 2022 and 27 July 2022, before the Order came into force, could contribute towards ECO4, with a notification window open until 30 September 2022¹². And the scheme's scope has a hard edge on new builds: suppliers can only deliver measures, apart from repairs, to pre-existing buildings erected before 1 April 2022, or premises first occupied as domestic premises before installation completion²¹.

The Warm Homes Programme: the wider scheme taking over

The umbrella under which ECO4's work continues is the Warm Homes Plan, with its target of upgrading 5 million homes³. But "Warm Homes Programme" also names a specific Welsh scheme, and the two should not be confused.

In Wales, the new Warm Homes Programme takes over from Nest as the Welsh Government's primary mechanism to tackle fuel poverty⁶. Its advice services will signpost people to and seek to leverage UK Government funding, including ECO4, the Great British Insulation Scheme and the Boiler Upgrade Scheme²². The Welsh Government has also been clear about the boundary between schemes: ECO4 and the Great British Insulation Scheme "are separate to the Welsh Government's Warm Homes Nest Scheme"¹⁷. Households in Wales can read more in our comparison of Nest Wales and the Warm Homes: Local Grant.

In England, the successor funding routes are the grant programmes under the Warm Homes Plan, principally the Warm Homes: Local Grant. The structural difference from ECO4 is funding source and blending rules. Under ECO4, "funding for measures delivered under ECO4 must not be blended with funding from other government schemes or grants", including the Warm Home Discount, the Boiler Upgrade Scheme, the Social Housing Decarbonisation Fund and the Home Upgrade Grant²³. The new grant programmes are designed to work differently, and households wondering what stacks with what can read our guide to combining energy grants.

The Great British Insulation Scheme, which runs alongside ECO4, is the clearest example of the change of approach. Ofgem describes it as follows: "unlike ECO4's 'whole house' approach, this scheme will mostly deliver single insulation measures"⁴. Where ECO4 aimed to lift a home's energy performance across the board, GBIS mostly funds one measure at a time, targeted at a wider range of households²⁴.

For energy independence, the shift is from depth to breadth. ECO4 concentrated deep funding on the lowest-income households in the least efficient homes; the successor landscape spreads shallower funding across more households, with the Boiler Upgrade Scheme carrying the heat pump transition on its own.

Other support running alongside: discounts, payments and the price cap

The end of ECO4 does not end bill support, and it is worth being clear about what continues.

• Warm Home Discount. The current scheme ends on 31 March 2026, but the government has decided to "continue the Warm Home Discount Scheme for a new 5-year scheme period from 2026/27 to 2030/31"⁵. The government's performance report confirms the "continuation of the Warm Home Discount until 2030-31"³.
• Energy price cap. The cap continues to be set by Ofgem, which published a formal response to the price cap aspects of the consultation on extending ECO4¹¹. For context on how far bills have moved, the Q4 (October to December) 2022 price cap was £3,371²⁵.
• Winter payments. The Winter Fuel Payment and Cold Weather Payments continue under their own rules, and households in crisis can turn to hardship funds and energy debt help.

These supports reduce a household's exposure to bills, but they do not reduce the household's dependence on the grid or on a supplier in the way retrofit does. A discount lowers the cost of the energy a home imports; insulation and heating measures lower the amount it needs. That is the gap left by ECO4's closure, and it is why the successor grant programmes matter more than the bill support that continues around them.

Measures and guarantees: what happens to insured work in progress

ECO4's measures list is broad, and it shows what is at stake when the scheme closes. The measures table covers boiler upgrades to non-renewable and renewable heating systems, repair or replacement of broken heating systems, first time central heating, electric storage heater upgrades, connection to district heating, heating controls, solar PV, wall, roof, floor and loft insulation, draught proofing, window glazing and higher performance external doors¹³.

The quality framework around those measures changed during the scheme. The 2025 legislation updated the standards: PAS 2030:2023 and PAS 2035:2023 replace the 2019 versions, and measures completed after the end of the transition period must be installed in accordance with the updated standards²⁶. Innovation measures must be a measure type listed in the PAS 2030:2023 annexes, a certified product under MCS, or certified by a person accredited to ISO/IEC 17065:2012²⁷.

Quality problems have been real. The Welsh Government's statement on UK Government action notes "poor quality workmanship by companies installing solid wall insulation" and "taking immediate action to suspend installers and protect consumers"¹⁷. The same statement gives the commitment on putting things right: "any works to correct deficiencies will be carried out swiftly and effectively, at the installers' cost"¹⁷.

For work in progress at the deadline, the rules are specific. The installation of a measure is deemed complete at handover, and measures must be completed in full no later than 31 December 2026¹². Once a project passes initial validation, "that project will move to a 'project in progress' status until all measures are notified"¹². Measures completed after 31 August 2022 must be notified by the end of the month after the measure was completed, and the final date for automatic notification is the end of March 2027¹². The time limit for completing a project runs from the date of completed installation of the first measure in the project¹³.

Two further deadlines sit inside this window. Applications to reassign savings must be made in writing on or before 31 July 2026²⁶. And under the standard alternative methodology, which has no specific measures cap under ECO4, applications may still be submitted beyond 31 March 2026²⁷.

Help for homes off the gas grid, including oil heating

ECO4's purpose has been to reduce heating costs for low income and vulnerable households by funding energy efficiency, insulation and heating measures, and that includes homes without a gas connection¹. Derbyshire County Council lists the support available to qualifying households: installing central heating where the home has no boiler or radiators, replacing storage heaters or coal fires with gas central heating, replacing a non-condensing combi boiler with a modern combi, and replacing a heat only boiler with a modern combi²⁸.

Private landlords face a specific restriction: they "can only access ECO to replace an old heating system with a renewable heating system if the existing EPC is an E, F or G"²⁸. Homes heated by oil have had routes through ECO4's heating measures, and our guide to energy grants for off-gas-grid homes covers the wider options, including help with heating oil costs in each nation.

In Northern Ireland, where ECO4 does not run, the equivalent support is changing on a similar timetable. The Warm Healthy Homes Fund will replace the current Affordable Warmth Scheme⁷, and nidirect's grants pages signpost the schemes available in each area¹⁰. Households there can read our comparison of NISEP and the Affordable Warmth Scheme.

For off-gas homes, the end of ECO4 removes the main supplier-funded route to a full heating system replacement. What remains is the Boiler Upgrade Scheme for renewable heating, nation-run schemes, and the successor grants, each with narrower scope than a whole-house ECO4 project.

Scotland-specific routes: retrofit services from Home Energy Scotland

Scotland participates in ECO4 through the flexible eligibility route: ECO4 Flex allows local authorities and the Scottish and Welsh governments, referred to in the scheme as Devolved Administrations, to refer households for support²³. Energy suppliers can also refer households under ECO4 Flex where they are struggling with persistent fuel debt or using prepayment meters and have regularly been unable to stay connected due to financial hardship²³.

Scotland's own retrofit provision has been renewed on a longer horizon than ECO4. The fuel poverty strategy set out the plan to replace the existing national scheme: "we propose to replace it with a new and enhanced 7 year national scheme"²⁹. That scheme, Warmer Homes Scotland, is covered in detail on our Scotland grants page, and its managing agent Warmworks handles delivery. The successor scheme's heating approach was set out in the heat in buildings strategy as "adopting a zero emissions first approach"³⁰, which points Scottish households towards heat pumps and away from replacement fossil boilers more firmly than ECO4 did.

One of the ECO4 Flex referral routes is particularly relevant in Scotland: a proxy under which a person in the household has been referred to the local authority for support by their energy supplier or Citizens Advice because they are struggling to pay their electricity or gas bills¹.

Households in Scotland therefore have two parallel systems: the UK supplier obligation until 31 December 2026, and the Scottish national scheme and advice services beyond it. Our comparison of Home Energy Scotland and Warmer Homes Scotland sets out which does what.

Applying before the scheme closes: how to qualify while ECO4 lasts

With the scheme closing on 31 December 2026 and no successor obligation, the practical question for a household that thinks it qualifies is what to do now.

1. Check the eligibility routes. ECO4's core route is based on benefits, and our pages on ECO4 eligibility and which benefits qualify set out the conditions. The flexible route, ECO4 Flex, lets local authorities and the Scottish and Welsh governments refer households that do not receive qualifying benefits²³.
2. Speak to an organisation offering free and impartial support. Councils advise residents to "speak to an organisation who can offer you free and impartial energy and bill saving support and assess whether you might be eligible for funding"³¹.
3. Contact any obligated supplier, not just your own. Ofgem's guidance is explicit: "You can contact any of the obligated energy suppliers to find out how they may be able to help you benefit from the ECO scheme, even if they are not your energy provider"²³.
4. Check your local route is still open. Some councils have already closed to new applications¹⁴, and delivery partnerships vary by area; Bridgend Council, for example, partners with E.ON on ECO4 Flex delivery, with E.ON checking applications for the council³¹.
5. Move quickly if a project is approved. Measures must be completed in full by 31 December 2026, and the project time limit runs from the first measure's completed installation date¹³.

The dependence to be honest about here: ECO4 funding comes through energy suppliers, recovered through bills, and delivered by installers contracted to them. A household receiving ECO4 measures gains insulation and heating it keeps, but the scheme itself is not something a household controls, and its closure date is fixed by government, not by the householder's readiness. That is the strongest argument for acting within the window rather than assuming an equivalent offer will exist in 2027.