The ECO3 Interim Delivery period ended on 30 June 2022, closing the three-month window in which energy suppliers could deliver measures under ECO3 rules and scoring. Ofgem, which administers the Energy Company Obligation schemes, records that the period ran from 1 April 2022 to 30 June 20221.
"ECO3 Interim Delivery allowed suppliers to deliver to ECO3 rules and ECO3 scoring methodology for three months between 1 April 2022 until 30 June 2022."
The successor scheme, ECO4, is enacted by the Electricity and Gas (Energy Company Obligation) Order 2022, as amended, and its overall obligation period runs from commencement on 27 July 2022 to 31 March 20261. Ofgem states that the scheme requires energy suppliers to achieve a total of £224.3 million in annual bill savings for domestic premises, and that suppliers must do so in full no later than 31 March 20261. Suppliers will also be able to transfer measures until 30 June 20261.
ECO4 is split into phases, with the first three given as follows1:
| Phase | Period |
|---|---|
| Phase 1 | 27 July 2022 to 31 March 2023 |
| Phase 2 | 1 April 2023 to 31 March 2024 |
| Phase 3 | 1 April 2024 to 31 March 2025 |
The guidance also sets out the minimum improvement expected of homes treated under the scheme, describing work to bring band D and E homes to at least a band C, and band F and G homes to at least a band D1. Delivery is handled through the supply chain, with YES Energy Solutions among the organisations that deliver ECO and related schemes.
Why it matters for households
The end of ECO3 Interim Delivery marked the point at which the rules and scoring used to assess installed measures changed. For a household, the practical effect sits in which measures count, how their savings are calculated and therefore what a supplier is willing to fund. The grants-schemes hub sets out the schemes available to households.
The ECO4 obligation is measured in bill savings rather than in a number of installations, so the target is expressed as £224.3 million in annual savings across domestic premises1. That figure describes the aggregate the scheme must achieve, not a sum available to any individual home. Eligibility for ECO4 rests on a set of conditions covering the property, its tenure and its occupants, and the guidance deals with these separately from the delivery rules.
Energy independence for a home, in this context, means the fabric of the building holding heat for longer and requiring less energy to keep warm. Insulation measures, glazing and heating measures are all treated as qualifying actions under the scheme, each with its own criteria1. The interim period mattered because it allowed work to continue under the previous rules while the ECO4 framework was being put in place.
What happens next
The ECO4 obligation period runs to 31 March 2026, with suppliers required to meet their targets in full by that date, and measure transfers permitted until 30 June 20261. The guidance also records later changes to the scheme, including the Electricity and Gas (Energy Company Obligation) (Amendment) Order 2025, which became law on 29 July 2025, and a coming into force date of 1 August 2025 for that order1. Ofgem notes that after 29 July 2025, areas in England and Wales with Rural Urban Indicator codes RLN1, RSN1, RSF1 and RLF1 are considered rural1.
Sources1 cited
- ECO4 Guidance: Delivery, ofgem.gov.uk