The Energy Company Obligation (ECO) is a UK Government scheme designed to improve household energy efficiency, reduce energy consumption, and lower carbon emissions. It helps eligible households make their homes warmer, more affordable to heat, and better for the environment.

ECO was first introduced in 2013 and has evolved through several phases. The latest phase, ECO4, runs from 2022 to 2026 and builds on the success of earlier versions, targeting support to low-income and vulnerable households.