How to Make Credible Green Marketing Claims (Green Claims Code)

The Green Claims Code is the CMA's guidance on environmental claims, and since 6 April 2025 it has teeth. The regulator can now investigate and penalise breaches of consumer law directly, without going to court, with fines of up to 10 per cent of global turnover. The code itself is not new and it is not complicated: six principles, published in September 2021. What has changed is the cost of ignoring them.

The six principles, in the CMA's own words

The code says green claims must:

1. Be truthful and accurate. Businesses must live up to the claims they make about their products, services, brands and activities.
2. Be clear and unambiguous. The meaning that a consumer is likely to take from a product's messaging and the credentials of that product should match.
3. Not omit or hide important information. Claims must not prevent someone from making an informed choice because of the information they leave out.
4. Only make fair and meaningful comparisons. Any products compared should meet the same needs or be intended for the same purpose.
5. Consider the full life cycle of the product. Claims can be misleading where they do not reflect the overall impact, or where they focus on one aspect of it but not another.
6. Be substantiated. Businesses should be able to back up their claims with robust, credible and up to date evidence.

Why the stakes changed in April 2025

For its first three and a half years the Green Claims Code was guidance with the ordinary consumer protection regime behind it, which meant the CMA had to go to court to enforce. That changed when the consumer protection provisions of the Digital Markets, Competition and Consumers Act 2024 came into force on 6 April 2025. The CMA can now investigate suspected breaches of consumer law itself, decide whether the law has been broken, and impose penalties of up to 10 per cent of a business's global turnover, without an intervening court judgment.

That is a step change in speed as much as in size. A vague sustainability line on a product page is now something a regulator can act on directly, and the number is a share of worldwide turnover rather than UK revenue.

Claims that reliably get businesses into trouble

• Bare absolutes. "Eco-friendly", "green", "sustainable" and "kind to the planet" with nothing attached. They fail principle 2 because the consumer fills in the meaning, and they usually fail principle 6 because there is no evidence file for a claim that was never defined.
• One-attribute claims about a many-attribute product. Recycled packaging on a product whose impact is overwhelmingly in use or in manufacture. That is principle 5.
• Carbon neutrality that rests entirely on offsets. If the phrase implies reduced emissions rather than purchased credits, the impression does not match the fact. Say what has been reduced, what has been offset, and how.
• Comparisons against a product nobody sells. "50 per cent less plastic" against an unstated baseline, or against a competitor product that does a different job, fails principle 4.
• Small print that carries the load. If the qualification is what makes the headline true, the headline is misleading. That is principle 3.
• Logos and colours doing the claiming. A green leaf device, an invented badge or a self-awarded certification mark is a claim, and the code applies to symbols, emblems, logos, graphics, colours and brand names as much as to words.

How to write a claim that holds up

Start with the evidence, not the copy. Decide what you can actually prove, then write the sentence. The reverse order is how businesses end up substantiating a marketing line after the fact.

Be specific and bounded. "Our 500ml bottle uses 30 per cent recycled PET" beats "made with recycled materials". A number, a scope and a date are harder to misread and easier to defend.

Name the comparison. If you say "lower carbon", say lower than what, measured how, over what period. The CMA's test for comparisons is whether the products meet the same need or are intended for the same purpose.

Keep a substantiation file. One document per claim, holding the underlying data, the methodology, the date it was produced and the person accountable for it. Diarise a review, because principle 6 asks for evidence that is up to date, and a life cycle assessment from four product generations ago is not.

Treat the whole life cycle as the default frame. If you are claiming about one stage, say which stage. "Recyclable in UK kerbside collections" is a claim about disposal and reads honestly as one.

Check who else has to agree. Advertising is also covered by the CAP and BCAP codes, enforced by the Advertising Standards Authority, which has run its own programme on environmental claims. Getting past marketing and legal internally is not the same as getting past either regulator.

A short internal process

1. Draft the claim and identify precisely what it asserts, including what a reader would infer.
2. Test it against all six principles in writing, not in a meeting.
3. Attach the evidence, with method and date, and name an owner.
4. Check the visual layer as well as the words: badges, colours, imagery, product names.
5. Review on a schedule, and pull the claim when the evidence stops supporting it.

This sits alongside the wider governance work covered in our guides to the circular economy in business and the reporting and disclosure obligations that increasingly come with it. For the rest of our ethics and sustainability guidance, start at E-Business Ethics.

Frequently asked questions

What is the Green Claims Code?

Guidance published by the Competition and Markets Authority on 20 September 2021, setting out six principles that environmental claims about goods and services must meet: truthful and accurate, clear and unambiguous, not omitting important information, fair and meaningful comparisons, full life cycle, and substantiated.

Is the Green Claims Code law?

The code is guidance, but it interprets consumer protection law, and breaching that law is what carries the penalty. Since 6 April 2025 the CMA has been able to enforce consumer law directly and impose fines of up to 10 per cent of global turnover.

Can I say my product is eco-friendly?

Not safely on its own. A broad term with no definition and no evidence behind it runs straight into the requirements to be clear and unambiguous and to be substantiated. Say what the product does, with a number and a scope.

Do the rules cover logos and colours?

Yes. The CMA describes green claims as being made through statements, symbols, emblems, logos, graphics, colours and product brand names, so a leaf device or a self-created badge is a claim like any other.

What counts as substantiation?

Robust, credible and up to date evidence, held before the claim is published. In practice that means the underlying data, the methodology, the date and a named owner, reviewed on a schedule.

Who else regulates green advertising in the UK?

The Advertising Standards Authority, through the CAP and BCAP codes, which apply to advertising content and have their own guidance on environmental claims. Compliance with one does not guarantee compliance with the other.

Sources

• CMA: Green Claims Code, check your green claims, for the six principles as quoted and the finding that 40 per cent of green claims made online could be misleading
• CMA: making environmental claims on goods and services, published 20 September 2021, for the full guidance and examples
• CMA: new consumer protection regime comes into force, for direct enforcement from 6 April 2025 and penalties of up to 10 per cent of global turnover

Checked on 16 September 2026. This is general guidance, not legal advice; take advice on any specific claim before publishing it.