Energy suppliers may transfer measures under the Energy Company Obligation 4 (ECO4) scheme until 30 June 2026, according to Ofgem's delivery guidance published on 8 December 20251. The overall obligation period for ECO4 ran from the commencement of the ECO4 Order on 27 July 2022 to 31 March 20261. Ofgem is the administrator of the ECO schemes1.
The transfer window mirrors the arrangement at the end of the previous scheme. Under ECO3, interim delivery allowed suppliers to work to ECO3 rules and scoring methodology for three months, from 1 April 2022 until 30 June 20221. The ECO4 guidance states the position in the same terms:
"Suppliers will also be able to transfer measures until 30 June 2026."
ECO4 places a legal obligation on energy suppliers to deliver energy efficiency measures to domestic premises, with each supplier's target based on its share of the domestic energy market in Great Britain1. The scheme requires suppliers to achieve a total of £224.3 million in annual bill savings for domestic premises, and to do so in full no later than 31 March 20261. The obligation period was divided into phases: Phase 1 from 27 July 2022 to 31 March 2023, Phase 2 from 1 April 2023 to 31 March 2024, and Phase 3 from 1 April 2024 to 31 March 20251.
The guidance also sets out the minimum energy performance standards that measures must achieve. Band D and E homes must reach at least band C, and band F and G homes at least band D1. Several rules changed during the scheme's life. After 29 July 2025, when the Electricity and Gas (Energy Company Obligation) (Amendment) Order 2025 became law, areas in England and Wales with Rural Urban Indicator codes RLN1, RSN1, RSF1 and RLF1 are considered rural1. Working Tax Credit and Child Tax Credit ceased to exist on 5 April 20251. A new version of the reduced data standard assessment procedure, RdSAP 10, was introduced on 15 June 2025 and replaced RdSAP 20121. From May 2024, operatives collecting customer data have been required to input the financial amount the consumer has contributed1.
Why it matters for households
The transfer window is an administrative arrangement between suppliers and Ofgem, not a route for householders to apply for work. It allows measures completed under the scheme to be moved between suppliers so they count towards the correct obligation target. For a household, the practical effect is that work already delivered under ECO4 can still be counted and closed out after the main deadline, rather than being invalidated by a timing gap.
The 31 March 2026 end of the obligation period is the date that matters for new delivery. The guidance does not describe any extension of the scheme itself beyond that date, and no successor scheme is set out in the document. Households considering energy efficiency work under grants and schemes should note that eligibility rules changed during ECO4's life, including the rural definition and the withdrawal of tax credits, and that the minimum standards require a home to reach at least band C from band D or E, or band D from band F or G.
What happens next
The transfer period closes on 30 June 20261. Ofgem's guidance does not state what happens to measures that remain untransferred after that date, and no further ECO4 delivery dates beyond the transfer window are given in the document1.
Sources1 cited
- ECO4 Guidance: Delivery, ofgem.gov.uk