ECO4 Flex vs the Help to Heat route: which eligibility path?

ECO4 has five eligibility routes, and the one a household uses decides who assesses it, what evidence is needed and who can be contacted when something goes wrong. The Help to Heat Group route turns on benefit entitlement. The four Flex routes turn on a referral from a local authority, a devolved administration or, in two cases, an energy supplier. Ofgem's own guidance lists them as Help to Heat Group, Social Housing, LA Flex, In-Fill and Supplier Flex¹.

The distinction matters because the two paths are not interchangeable. A household on a qualifying benefit is assessed against the benefit list. A household not on a qualifying benefit can still be referred, but only if a participating council or devolved administration has published a statement of intent and considers it low income, fuel poor or vulnerable to the effects of living in a cold home¹. Councils take part voluntarily, so the route exists in some areas and not others.

Both paths lead to the same scheme. ECO4 runs from 27 July 2022 to 31 December 2026 and is split into four phases, with suppliers able to deliver up to 50 per cent of their obligation through Flex². Ofgem administers the scheme, sets targets for each obligated supplier and monitors progress, but it does not decide individual eligibility¹.

The five ECO4 eligibility routes at a glance

The routes are not five versions of the same test. They are five different ways a property and household can be shown to qualify, and each carries its own evidence burden.

The Help to Heat Group is the benefit-based route. Social Housing covers social tenants through their landlord rather than through a household application. LA Flex is the local authority referral route, and Supplier Flex is the supplier-led version of the same idea, restricted to households in persistent fuel debt or on prepayment meters who have regularly been unable to stay connected¹. In-Fill allows measures to be delivered to premises that would not otherwise qualify, sitting alongside the other routes rather than replacing them³.

The Flex routes themselves are numbered. Route 1 is a broad income-based test, Route 2 uses a set of proxies, Route 3 covers households referred by a GP, Health Board or NHS trust on health grounds, and Route 4 is bespoke targeting approved by the government⁵. Suppliers may only provide evidence for Routes 2 and 4, which is why a household approaching a supplier directly will usually be funnelled into one of those two⁵.

The published route counts differ between documents. Ofgem's current homeowner guidance lists five routes¹. Ceredigion County Council's own Flex page describes three available routes for its area⁴, and an earlier Ofgem statement of intent template refers to four⁶. A household should treat the council's published statement of intent for its own area as the operative document.

Help to Heat: the route based on benefits and household circumstances

The Help to Heat Group is the route most households recognise. It works from a fixed list of benefits rather than from a council's judgement, and the list is set out in the delivery guidance:

• income-based Jobseeker's Allowance
• income related Employment and Support Allowance
• Income Support
• Pension Credit Guarantee Credit
• Universal Credit
• Housing Benefit
• Pension Credit Savings Credit
• Child Benefit, subject to income caps and household composition³

Because the test is entitlement rather than discretion, the Help to Heat route does not depend on whether a council has opted into Flex. A household receiving one of those benefits can approach a participating energy supplier directly, and Ofgem publishes the list of participating suppliers⁷. That is the practical difference: the Help to Heat route is available wherever the household is, while the Flex routes depend on a local authority having chosen to take part.

The route also carries the least paperwork for the household, because the qualifying evidence is the benefit award itself rather than a proxy assessment or a medical letter. Where a household is on a benefit that is not on the list, or is just above an income threshold, the Flex routes are the alternative, and the two are frequently confused because both end in the same installer and the same measures.

For energy independence, the distinction is about who holds the decision. Under Help to Heat, the gatekeeper is the supplier and the test is national. Under Flex, the gatekeeper is a council that has volunteered to run the scheme, which means the route can close or change with local priorities. A household relying on Flex is relying on a local decision that sits outside its own control, and that is a real limit on how far the grant can be treated as a dependable route to a warmer, less grid-dependent home.

LA Flex: how local authority referral widens eligibility

LA Flex exists to reach households that the benefit test misses. Ofgem describes it as allowing local authorities and the Scottish and Welsh governments, referred to in the scheme as devolved administrations, to identify low-income or vulnerable households who are not in receipt of the means tested benefits that would make them eligible for ECO, but who may benefit from energy efficiency improvements¹.

The mechanism is a published statement of intent. A participating local authority can refer private tenure households that it considers to be living in fuel poverty or on a low income and vulnerable to the effects of living in a cold home⁸. All local authorities in England, Wales or Scotland are able to make referrals through Flex, so the route is not restricted by nation, though it is not available in Northern Ireland⁹.

Route 2 is the proxy route and the one most households meet. It requires at least two of the listed proxies, with proxies 1 and 3 unable to be used together and proxy 5 unavailable in at least one council area⁴. The income limit attached to Route 1 is a total combined gross annual income from all sources of less than £31,000⁴. Route 3 covers households identified and referred by a GP, a Health Board or an NHS trust, and a letter from the GP, Health Board or NHS Trust confirming the health condition must be supplied with a completed application form⁴.

Property conditions apply alongside the household test, and they differ by route:

The property must be an occupied private domestic premises, either owner-occupied or private rented⁴.

The independence point is straightforward. Flex widens who can qualify, but it does so through a council that has chosen to participate, using a statement of intent that can be superseded. Birmingham's own statement of intent has been superseded twice, in August and November 2024¹¹. A household that qualifies today is relying on a local framework that is not permanent.

Social Housing, In-Fill and Supplier Flex: the remaining routes

The three remaining routes cover cases the first two do not.

Social Housing is the route for social tenants, delivered through the landlord rather than through a household application, and it appears on the eligibility requirements form alongside LA Flex and Supplier Flex¹³. In-Fill is different in kind: it allows eligible measures to be delivered to eligible domestic premises including those delivered via LA Flex and in-fill, which means a property can receive measures as part of a wider project even where it would not independently pass a route test³. In-Fill is excluded from the household declaration mechanism, so a premises occupied by a household declared by a relevant authority as meeting one of the four ECO4 Flex referral routes is treated separately from in-fill delivery⁹.

Supplier Flex is the supplier-led version. Energy suppliers can refer households under ECO4 Flex where they are either struggling with persistent fuel debt and are supported by suppliers, or are using prepayment meters and have regularly been unable to stay connected to their fuel supplies due to financial hardship¹. This is the narrowest of the routes in practice, because it depends on the supplier's own records of the household rather than on a council assessment or a benefit award.

Suppliers can deliver up to 50 per cent of their obligation through Flex, and delivery under Flex is optional for suppliers⁵. That optionality is the key limit. A supplier that chooses not to use Flex, or that has already filled its Flex allowance, is not obliged to take a referral, even where a council has issued a declaration. The household's route to a measure therefore depends on two separate voluntary decisions: the council's decision to participate and the supplier's decision to deliver.

What Ofgem's role means for your application

Ofgem administers ECO4, sets targets for each obligated energy supplier, ensures compliance and monitors progress towards those targets¹. It is not an eligibility service. Ofgem states that it cannot provide pre-approval or confirm eligibility before a full application is submitted by your installer¹⁴.

That position is worth stating plainly because it is the single most common misunderstanding about the scheme. A household cannot ask Ofgem whether it qualifies. The eligibility decision sits with the referring local authority under Flex, or with the supplier under the Help to Heat Group, and Ofgem's involvement begins once a measure has been notified.

Ofgem's powers are supervisory. It uses information gathering powers under the ECO4 Order to require suppliers to provide information about proposals, evidence of compliance and costs of achieving obligations². Where it identifies non-compliance or suspected non-compliance, its formal enforcement powers can include opening investigations, making orders and imposing penalties¹⁵. It administers 12 schemes on behalf of the UK government and the devolved administrations, so ECO4 sits within a wider compliance function rather than being handled in isolation¹⁵.

Ofgem also does not get involved in individual complaints about energy suppliers or network operators, and does not investigate individual disputes¹⁶. A household with a complaint about how its application was handled goes to the supplier, the council or the installer, and ultimately to the Energy Ombudsman, not to Ofgem. Ofgem's monitoring duties cover whether suppliers meet the rules in licences, regulations and law and reply quickly to customers, and it will start an investigation if it thinks a supplier has not met certain rules¹⁶.

Audits, due diligence and what happens if checks fall short

Flex declarations are audited, and the audit window outlasts the scheme. Applications and declarations may be subject to Ofgem audits during the time that ECO4 is in effect and up to three years after the scheme ends⁴.

The audit process itself was formalised during the scheme's life. Paragraphs 8.7 to 8.9 were added to the delivery guidance in regard to the ECO4 Flex audit process¹⁷. Ofgem publishes the results of the ECO4 Flex audits, the framework, stakeholder expectations, role and responsibilities and actions for local authorities and suppliers¹⁸. Ofgem will send suppliers an annual sample of measures that they have notified throughout the duration of the year, and where it identifies that local authorities have not carried out adequate due diligence checks, it will include this in the report⁹.

The consequences of a failed check fall on the measure, not only on the paperwork. Any evidence of electronically duplicated or forged signatures will be investigated, and any measures where suspected fraudulent activity is detected will be rejected¹⁹. That is a scheme rule rather than a warning about individual cases, and it applies to declarations as much as to installation records.

The audit regime has a wider effect on how councils behave. Ofgem's reporting of inadequate local authority due diligence checks means a council's referral practice is itself subject to scrutiny, which is one reason statements of intent are drafted tightly and reviewed. For a household, the practical implication is that the evidence collected at application stage, income details, health letters, tenure documents, is what will be examined later. Ofgem's wider audit record shows the scale it works at: in Scheme Year 11 it conducted 1,199 audits, made up of 621 desk audits and 578 site audits, with statistical audits randomly selected to provide a representative view of the scheme population at a 90 per cent confidence level²⁰.

Key deadlines for notifications and transfers

The deadlines that matter to a household are the scheme end and the transfer window, not the phase notification dates that apply to suppliers.

ECO4 runs until 31 December 2026, and Birmingham City Council states that it will continue nationally until December 2026 to only allow energy suppliers to complete outstanding remedial works and cover any overspend in their current targets². That wording matters: the final period is for completing work already in train rather than for new applications.

Suppliers may apply to transfer ECO4 measures and projects on or before 31 March 2027, and all project notifications are subject to an overall scheme deadline of 31 March 2027². Measures included in the automatic 5 per cent route must be notified by the end of March 2027². Ofgem will notify all suppliers of its final determination no later than 30 June 2027 and submit its final report to the Secretary of State by that date².

The earlier phase deadlines are historical and apply to suppliers' customer number notifications rather than to households: August 17 2022, 1 February 2023, 1 February 2024 and 1 February 2025². A household does not act on these dates, but they explain why a supplier's appetite for new Flex referrals changes through the scheme's life.

For a household weighing the two paths, the deadlines sharpen the choice. The Help to Heat route depends on a benefit award that can be evidenced at any point before the scheme closes. The Flex route depends on a council declaration, a supplier willing to deliver, and enough time left in the scheme for the measure to be installed and notified. Where a household is near the boundary of either test, the benefit route carries fewer moving parts and fewer parties whose decisions it does not control.