Energy suppliers are at the heart of the main home energy-efficiency schemes — not as a favour, but because the law requires it. If you have been offered free or subsidised insulation or heating through ECO4 or a similar grant, an obligated supplier is usually the organisation ultimately funding it. Understanding that role explains why the offer exists and what you are entitled to expect.
Obligated suppliers under ECO
The Energy Company Obligation (ECO) places a legal duty on larger domestic energy suppliers to deliver energy-efficiency and heating measures to eligible households. Under the current scheme, ECO4, this is focused on low-income, fuel-poor and vulnerable households through what is known as the Home Heating Cost Reduction Obligation. In practice, this means an obligated supplier:
- Funds the measures – the cost of qualifying work is met to help lower your bills and warm your home.
- Meets a target – each obligated supplier must deliver a set amount of energy savings, overseen by Ofgem.
- Works through registered trades – the installation itself is carried out by TrustMark-registered, appropriately certified installers.
What it means for you
You do not have to be a customer of the funding supplier to benefit, and you should never be asked to hand over money for a measure that a scheme is meant to fund. The obligation is monitored by Ofgem, so if an offer feels wrong — unexpected upfront charges, pressure to sign quickly, or vague credentials — that is a reason to check before agreeing.
Suppliers also carry wider duties toward customers in difficulty, separate from these schemes. For your rights with your own supplier and help with bills, see our energy and water section, and for the schemes themselves our grants overview.