ECO4, ec04, eco4, or E.C.O.4? How to Say It and What It Means

If you’ve searched for ECO4, ec04, eco4, or even E.C.O.4, you’re not alone. The term appears in many forms, leading to understandable confusion. This guide explains exactly what ECO4 is, the correct way to pronounce it, and why the different spellings still refer to the same scheme.

ECO4 stands for Energy Company Obligation Phase 4. It is a UK government energy efficiency scheme that runs from 2022 to 2026. The aim of ECO4 is to help improve the energy performance of homes, particularly for low-income households or those living in properties that are expensive to heat.

The scheme provides funding for energy-saving measures such as insulation, heating upgrades, and renewable energy installations. The goal is simple: reduce carbon emissions and lower energy bills across the UK housing stock.

You may hear or read a variety of pronunciations or spellings:

• ec04
• eco4
• ECO4
• E.C.O.4

The correct and widely recognised way to say it is eco-four—with “eco” pronounced as in “ecology” followed by the number four.

There is no need to spell out the letters individually (E.C.O.). Saying “eco-four” is clear, professional, and universally understood within the energy and construction sectors.

Press play on the audio file to listen to the correct pronunciation.

The scheme is often typed as ec04, eco4, or E.C.O.4 in online searches, on application forms, and even by energy companies. Regardless of the variation, all refer to the same Energy Company Obligation Phase 4 programme.

If you have typed any of these versions—ec04, eco4, or E.C.O.4—you have arrived at the right place.

Official name	ECO4
How to say it	eco-four (like “ecology four”)
Other common spellings	ec04, eco4, E.C.O.4

Using the correct pronunciation helps avoid miscommunication, particularly when speaking with contractors, energy providers, or when applying for support. It also distinguishes ECO4 from product codes or regulatory references where letter-by-letter pronunciation is standard.

Whether you arrived here searching for ec04, eco4, or E.C.O.4, they all point to the same valuable scheme: ECO4. Now you know how to say it, and what it stands for, you can talk about it confidently and professionally.