ECO4, and the 31 December 2026 deadline

If you search for ECO4 today you will find pages saying it ended in March 2026, pages saying it runs to December 2026, pages saying it is ongoing with no end date, and pages saying no successor has been announced. Almost none of them carries a date.

Here is the position, with sources.

Current position

ECO4 was extended by nine months and closes on 31 December 2026. There will be no ECO5 — the supplier obligation model is not being renewed. What follows is grant funding under the Warm Homes Plan, published on 21 January 2026, with Warm Homes: Local Grant already operating as the low-income route.

The “ended in March 2026” claim is a real event attached to the wrong scheme. The Great British Insulation Scheme ran from April 2023 and was scheduled to end in April 2026; the government confirmed it would not be extended. GBIS funded insulation measures. It never funded solar.

How ECO4 works

This is where the advertising and the scheme part company.

ECO4 is an obligation placed on larger energy suppliers to deliver energy efficiency measures to low-income and vulnerable households. Suppliers meet it through contractors. You do not apply to a government department; you are assessed, and the property is modelled.

Critically, it operates on a whole-house basis. The assessment looks at the property’s overall performance and funds the measures that move it furthest, which in a poorly insulated home is almost always insulation, and in a home with failing heating is the heating.

Who qualifies

The extension did not change eligibility. Broadly, households that either:

• receive a qualifying means-tested benefit: Universal Credit, Pension Credit, income-based JSA or ESA, Income Support, or certain tax credits; or
• are referred by their local authority or energy supplier under LA Flex, which lets councils extend eligibility to households they judge to be in fuel poverty or living with a health condition made worse by a cold home.

LA Flex is the route worth knowing about, because it reaches households that fail the benefit test. Criteria are set locally and differ by authority.

The deadline is earlier than it looks

Measures generally need to be installed and notified before the closing date, not merely applied for. Surveys, modelling, contractor scheduling and installation take months, and suppliers stop taking new work well ahead of a scheme close to avoid stranded projects.

The government has not published a single national “last application” date. Suppliers and delivery partners may set earlier intake cut-offs so measures can be completed, so ask the organisation handling your case for its date rather than relying on an estimated deadline.

Should you wait for the Warm Homes Plan instead?

No. The Warm Homes Plan is already running through existing delivery schemes.

The Warm Homes Plan is not a future scheme with an opening date. It was published on 21 January 2026 and is already delivering, through Warm Homes: Local Grant and the Warm Homes Social Housing Fund. Those two are to be integrated into a single low-income capital scheme from 2027/28, which is an administrative change rather than a start date.

So there is nothing to wait for. If you qualify for ECO4 you very likely qualify for Warm Homes: Local Grant too, and that one does not close on 31 December.

The two compared in detail.

What to do next

• Check whether you meet the benefit test, or whether your council operates LA Flex.
• Find your EPC rating on the government EPC register: it is free and takes thirty seconds.
• Expect the assessment to lead with insulation or heating, and treat solar as a possible addition rather than the request.
• Move now rather than in December. The practical deadline is months earlier than the formal one.
• Be sceptical of anyone who contacts you about ECO4 unprompted.

The eligibility checker runs those first two questions in your browser and tells you where you stand: including when the answer is that nothing currently fits.