ECO4 is the fourth phase of the Energy Company Obligation, a supplier-funded scheme that pays for energy-efficiency upgrades (insulation, heating system replacements, ventilation) for low-income and vulnerable households in England, Wales and Scotland.
The scheme ran from 1 April 2022 to 31 March 2026, with the successor framework taking over from April 2026; in-flight ECO4 installations still complete under ECO4 rules.
Last reviewed: May 2026
TL;DR
- Two gates apply: a means-tested benefit (Universal Credit, Pension Credit Guarantee, JSA, ESA, Income Support, Child or Working Tax Credit, Housing Benefit) and a pre-improvement EPC band of D, E, F or G.
- Measures must take the property to at least EPC band C, or achieve a two-band uplift, whichever the supplier's whole-house plan delivers.
- England, Wales and Scotland are in scope; Northern Ireland runs its own Affordable Warmth scheme separately.
- LA Flex routes let local councils refer non-benefit households whose income or vulnerability profile meets local published criteria.
- Ofgem's ECO4 statistics show roughly 220,000 measures delivered between scheme launch and end-2025 in the published monthly dataset.
The two gates that decide ECO4 eligibility
ECO4 has two parallel routes onto the scheme.
Both run off the same household but use different criteria.
The main route is Help to Heat. The household must include at least one person receiving a qualifying means-tested benefit. The property must hold a pre-improvement EPC rating of D, E, F or G (the worst-performing bands). The measures the obligated supplier installs must take the property to EPC band C, or achieve a two-band uplift in efficiency where reaching C is technically impossible. Solid-walled stone cottages and pre-war terraces routinely sit in the two-band-uplift carve-out. The second route is LA Flex (Local Authority Flexible Eligibility). Each council in England, Wales and Scotland publishes a Statement of Intent on its website setting the local income, vulnerability or health criteria a household must meet to be referred under LA Flex. The household does not need to be on a means-tested benefit; the council confirms eligibility against its published criteria.
Qualifying benefits in detail
The benefits list is fixed in the ECO4 Order 2022 (the statutory instrument that sets the scheme). The household qualifies if at least one resident receives one or more of the following:
- Universal Credit
- Pension Credit Guarantee Credit
- Income Support
- Income-based Jobseeker's Allowance
- Income-related Employment and Support Allowance
- Child Tax Credit (subject to income thresholds)
- Working Tax Credit (subject to income thresholds)
- Housing Benefit
- Child Benefit (subject to income thresholds, added in the April 2023 ECO4 amendment)
Pension Credit Savings Credit alone is not a qualifying benefit. The household must hold the Guarantee element. The catch is that many older households receive only Savings Credit, having missed Guarantee Credit by a small margin of pension income, and assume they qualify because "they get Pension Credit". Eligibility checks fail at the DWP data match.
EPC band gate: D, E, F or G pre-improvement
The pre-improvement EPC must show D, E, F or G. Band C and band B properties do not qualify even if the resident is on benefits, because the scheme is designed for the most heat-leaky homes. The current EPC must be lodged on the Domestic EPC Register and dated within the last 10 years; if there is no live EPC, the obligated supplier's retrofit assessor will produce one as part of the whole-house plan.
Here is where it breaks: a household in a newer post-2000 estate, even on Universal Credit, is unlikely to qualify because the property is already at band C or higher. ECO4 was deliberately tilted toward old housing stock because that is where the carbon and bill savings are.
| Pre-improvement EPC band | ECO4 in scope | Typical retrofit pathway under ECO4 |
|---|---|---|
| A or B | No | Not eligible |
| C | No | Not eligible (already at target band) |
| D | Yes | Cavity wall insulation, loft top-up, boiler upgrade to reach C |
| E | Yes | Cavity or solid wall insulation, loft, ventilation, room-in-roof, possible heating system change |
| F | Yes | Solid wall insulation, full heating, ventilation, often a two-band uplift to D as practical maximum |
| G | Yes (priority) | Whole-house package; two-band uplift to E or D typical for solid-wall heritage stock |
The whole-house plan and the two-band uplift carve-out
ECO4 marked a structural change from ECO3. Under ECO3 (2018 to 2022), suppliers could install a single measure (a loft top-up, a boiler) and claim the carbon and cost saving. Under ECO4, suppliers must produce a whole-house plan covering every cost-effective measure, and they must install the package that gets the property to EPC C or two bands higher.
The whole-house plan is led by a Retrofit Coordinator working to PAS 2035, the national standard for domestic retrofit. The coordinator surveys the property, produces a Whole-House Assessment, lays out the measure sequence, and signs off the delivery. The supplier funds the work; the household contributes nothing in most cases.
In practice, the household will see a retrofit assessor (a separate person from the installer) on site for two or three hours, often before any installer quote lands. The assessor's report is filed on TrustMark's data warehouse, which is the central scheme-wide audit trail.
Devolved-nation rules: ECO4 in Scotland and Wales
ECO4 is GB-wide for the obligated supplier funding, but the on-the-ground delivery and the parallel grant schemes diverge.
Scotland runs Warmer Homes Scotland (administered by Warmworks) and Home Energy Scotland loans alongside ECO4. Many Scottish households eligible for ECO4 are routed through the Scottish Government schemes first because they offer broader measure coverage (electric storage heating replacement, for example) and Home Energy Scotland acts as the single point of contact. The ECO4 funding lands as a top-up on the Scottish Government's underlying spend.
Wales runs Nest, administered by the Energy Saving Trust on behalf of the Welsh Government. Nest is the front door for fuel-poor households in Wales; ECO4 funding tops up Nest's delivery. Eligibility criteria are aligned but not identical.
Northern Ireland sits outside ECO entirely. The Affordable Warmth Scheme is administered by NIHE and the Department for Communities. Eligibility is income-based (household income under a published threshold) rather than benefits-based. The two schemes do not interlock.
What ECO4 actually pays for: measures and order of operations
The PAS 2035 whole-house plan dictates the measure sequence. The standard order, where the property structure allows, runs:
- Loft insulation (top-up to 300mm or first-time install)
- Cavity wall insulation, where the property has a cavity construction
- Solid wall insulation (internal or external), where there is no cavity
- Room-in-roof insulation
- Ventilation upgrade (mechanical extract ventilation or MEV, to deal with the air-tightness gain)
- Heating system change (boiler upgrade, first-time central heating, or in some cases an air-source heat pump)
- Heating controls (smart thermostat, zonal valves)
Solar PV is not a standard ECO4 measure in the way the parallel ECO+ / Great British Insulation Scheme treats it. PV under ECO4 only appears in specific innovation pathways and is the exception.
Heat pumps under ECO4
An air-source heat pump can be installed under ECO4 where the whole-house plan shows it is the most cost-effective route to band C, the property has the required insulation levels post-retrofit, and there is space for the outdoor unit and the hot water cylinder. In practice, ECO4 heat pump installs are concentrated in off-gas-grid properties (largely rural England, Wales, and the Scottish Highlands and Islands) because the carbon saving against the existing fuel (oil, LPG, electric storage) is largest there.
LA Flex: how local councils widen the eligibility net
LA Flex lets councils refer households outside the means-tested benefits gate. A household on a modest income, with a child with asthma, in a poorly insulated home, will not show on a DWP data match but may meet the local council's published vulnerability criteria. The council signs a Declaration form and the supplier accepts it as eligibility evidence.
Each council publishes its own Statement of Intent on its website. The criteria vary widely: some councils use Council Tax Reduction as a proxy, some use income thresholds (often capped at £31,000 household income), some use proxies like Free School Meals or a health professional's referral.
On the ground, LA Flex is the route that brings working low-income households into ECO4, the group most likely to fall through the cracks of the benefit-gated routes. Citizens Advice 2025 policy briefings describe LA Flex as the highest-friction route because applicants need to contact the council directly, navigate the local Statement of Intent, and supply income documentation. Most retrofit installers do not chase LA Flex referrals because the back-office cost per measure is higher than a benefits-gated referral.
The April 2026 transition: ECO4 to the next phase
ECO4 ended for new applications on 31 March 2026. In-flight measures with a lodged whole-house assessment and a contracted installation date continue to delivery under ECO4 rules. The successor scheme (sometimes referred to as ECO5 or as the next phase of the Great British Insulation Scheme) took over for new referrals from April 2026 with substantially similar eligibility gates and a continued PAS 2035 framework.
The published Ofgem ECO4 statistics dataset (monthly release) shows the final-period installation peak: roughly 18,000 measures recorded in January 2026 alone as suppliers cleared in-flight pipelines before the cut-off. Households whose assessment had been completed but installation not yet booked were the highest-risk group during the transition.
How to actually apply
Three doors in. Each leads to the same end point.
The supplier-direct route: call the household's electricity or gas supplier (or any obligated supplier; the customer does not have to be a customer of that supplier to be assessed). The supplier's ECO team books a retrofit assessor visit.
The council route: contact the local authority's energy or housing team and ask about LA Flex. The council will send the Statement of Intent and the Declaration form.
The intermediary route: charity or trusted scheme (the Energy Saving Trust, Citizens Advice, local Home Improvement Agencies). These bodies broker the referral to a supplier and add a layer of consumer protection by checking the installer is TrustMark-registered.
The catch is that ECO4 cold-callers have been a persistent issue throughout the scheme. Doorstep approaches offering "free insulation under a government grant" should be checked against the supplier's published partner list before any signature lands on a contract.
Frequently asked questions
Can a homeowner with no benefits qualify for ECO4 at all?
Only through LA Flex. The household must meet the local council's published criteria (income, vulnerability or health-based) and obtain a signed Declaration form from the council. The benefits gate cannot otherwise be bypassed.
Does private tenant status block an ECO4 application?
No. Private tenants on a qualifying benefit can apply, but the landlord must consent in writing because the measures alter the property fabric. Social tenants in housing-association stock are usually routed through the landlord's planned retrofit programme.
What if the EPC on file is wrong or out of date?
The retrofit assessor produces a fresh EPC under PAS 2035 as part of the whole-house plan. The supplier accepts the new EPC as the eligibility-gate evidence. The old EPC does not need to be challenged separately.
Can ECO4 fund a heat pump install end-to-end?
Yes, where the whole-house plan supports it and the property reaches the required insulation levels post-retrofit. Heat pump installs under ECO4 are heavily weighted toward off-gas-grid rural properties.
Is ECO4 means-tested on savings or only on benefits?
The benefits gate is the operative test. Savings are not checked directly under ECO4 unless the LA Flex route invokes a local income or asset threshold.
What recourse if the installer does poor work under ECO4?
Every ECO4 measure is registered with TrustMark and covered by the relevant guarantee body (IAA, QANW, GDGC depending on measure type). A complaint goes first to the installer, then to the guarantee body, then to the supplier's ECO complaints team, then to the Energy Ombudsman where the supplier is the obligated party.