The CMA Green Claims Code: the six principles explained

If you sell in the UK and put any environmental message on a product, an ad, or a website, this is the standard you are measured against. Here is each of the six principles, what the CMA expects under it, and the wording that usually trips it.

Principle 1 — Claims must be truthful and accurate

The claim must be true and must not create a false overall impression, even if each word is technically defensible. The classic failure is an offset-based "carbon neutral" line: it reads to a shopper as "this product caused no emissions," when in reality emissions happened and were offset elsewhere. That gap between the impression and the reality is what fails Principle 1.

Principle 2 — Claims must be clear and unambiguous

The meaning a consumer takes from the claim must match what you can actually stand behind. Blanket words like "green", "eco" or "sustainable" leave the shopper to fill in the benefit themselves — and they usually fill it in more generously than the facts justify. The CMA expects vague virtue-words to be made specific: say what is better, and by how much.

Principle 3 — Claims must not omit or hide important relevant information

Leaving out a material fact can mislead just as much as stating a false one. "Biodegradable" that only works in an industrial composter, or "carbon neutral" that omits its reliance on offsets, both mislead by omission. If a caveat changes how a reasonable person would read the claim, it has to be there — and close enough to the claim to be seen.

Principle 4 — Comparisons must be fair and meaningful

"Greener than", "better for the planet than", "more sustainable than the old version" — comparisons need an equivalent, verifiable methodology across the things being compared, and the basis of the comparison must be clear. Comparing your best-case figure against a competitor's worst case, or against an unstated baseline, is not a fair comparison.

Principle 5 — Claims must consider the full life cycle

A claim that is true of one stage but not the whole product overstates the real benefit. Recycled content in the product but landfill-bound packaging; a low-carbon use phase but a high-carbon manufacture — a claim has to reflect the full life cycle, or be scoped precisely to the stage it actually covers.

Principle 6 — Claims must be substantiated

Every claim needs clear, accessible, credible evidence a consumer could actually reach — a life-cycle assessment, test data, or independent verification. "Substantiated" is not "we believe it's true"; it is proof you hold and can show. No evidence, no claim. This is the single most common point of failure.

The Code reaches beyond your sentences

A frequent surprise: the six principles apply to your whole impression, not just your copy. The CMA treats a brand or product name that implies an environmental benefit, a self-made "eco" badge, a leaf motif, or a green colour palette as claims in their own right. If the overall impression says "good for the planet," every one of the six principles has to hold up — even when no sentence says it out loud.

Why the principles bite now

The Code has existed since 2021, but for years the CMA had to go to court to act on a breach. The DMCCA 2024 changed that: since 6 April 2025 the CMA can decide for itself that a business has breached consumer law and impose a fine directly, up to £300,000 or 10% of worldwide turnover, whichever is greater. The six principles are the lens the CMA uses to judge an environmental claim — so passing all six is now a commercial safeguard, not just good practice.

Frequently asked questions

Sources

• CMA Green Claims Code (2021), the six principles — Competition and Markets Authority guidance. gov.uk — Green Claims Code: making environmental claims
• Full guidance: "Making environmental claims on goods and services" — the detailed CMA guidance behind the six principles. gov.uk — How to make environmental claims about products and services
• Digital Markets, Competition and Consumers Act 2024 — Part 3 (direct enforcement of consumer protection law) and Part 4 (protection from unfair trading), in force 6 April 2025. legislation.gov.uk/ukpga/2024/13

Content current as of 9 July 2026. The Code and the DMCCA regime can change — re-check the primary source before acting on anything time-sensitive.