Greenwashing Explained: UK Rules and How to Avoid It

Greenwashing is one of the fastest ways for a business to turn a genuine sustainability effort into a legal and reputational problem. It means making an environmental claim that is misleading, exaggerated or simply cannot be backed up, and the UK rules on it now carry real teeth. This guide explains what greenwashing is, the UK rules that apply, and the practical steps to make environmental claims you can stand behind.

What greenwashing actually is

Greenwashing covers any environmental claim that gives a more positive impression than the facts justify. It is rarely a bare-faced lie. Far more often it is one of these subtler forms:

• Vague claims. Words like green, eco-friendly, natural or sustainable used with no explanation or evidence of what they mean.
• Selective claims. Highlighting one green feature while staying quiet about a much bigger environmental harm elsewhere in the product or business.
• Unsubstantiated claims. Statements such as carbon neutral or recyclable that the business cannot actually prove.
• Misleading imagery. Leaves, green colours and nature scenes used to suggest a benefit that is not really there.

Understanding where greenwashing sits within honest business conduct is part of a wider picture. Our pillar on what business ethics is sets out why credibility and honesty underpin everything a responsible company says about itself.

The UK rules on environmental claims

Two things have changed the landscape for UK businesses making green claims: clear guidance on what good looks like, and, more recently, strong powers to enforce it.

The CMA Green Claims Code

In 2021 the Competition and Markets Authority (CMA) published the Green Claims Code, guidance to help businesses make environmental claims that comply with consumer protection law. It is built on six principles. Claims must be:

• truthful and accurate;
• clear and unambiguous;
• free of important omissions, so nothing significant is hidden;
• fair and meaningful in any comparison they make;
• considerate of the full life cycle of the product or service;
• substantiated, with solid evidence held to back them up.

The code is the practical checklist every marketing and product team should run a green claim through before it goes out.

The DMCC Act 2024 and real enforcement

The bigger shift is enforcement. The Digital Markets, Competition and Consumers Act 2024 came into force for consumer protection on 6 April 2025, and it hands the CMA direct enforcement powers. The regulator can now decide for itself that a business has breached consumer law and impose penalties, rather than having to take the matter to court first. Fines can reach up to 10 per cent of a business's global annual turnover. Misleading green claims fall squarely within these powers, and the CMA has signalled that environmental claims remain an enforcement priority.

Advertising rules

On top of this, the Advertising Standards Authority and the CAP Code police environmental claims in advertising. The ASA regularly rules against adverts that make unqualified or misleading green claims, and its decisions are public, which adds a reputational cost to the regulatory one.

How to make honest green claims

Staying on the right side of the rules is mostly common sense applied consistently. Before you publish any environmental claim:

• Be specific. Replace vague labels with a precise, checkable statement, for example naming the recycled content rather than just saying recyclable.
• Hold the evidence first. Gather the data and, where relevant, third-party verification before the claim goes live, not after a challenge.
• Tell the whole story. Do not trumpet one benefit while hiding a larger impact; consider the full life cycle.
• Compare fairly. Only compare like with like, and make the basis of the comparison clear.
• Qualify conditions. If a claim only holds under certain conditions, such as recyclable only where facilities exist, say so plainly.

Building this discipline into how you communicate is part of a credible sustainability strategy. For the reporting side, see our guide to UK ESG reporting requirements, and explore more practical guidance on the E-Business Ethics homepage.

Frequently Asked Questions

What is greenwashing?

Greenwashing is when a business makes an environmental claim about its products, services or operations that is misleading, exaggerated or unsubstantiated. It can be an outright false claim, but more often it is a vague or selective one, such as labelling something eco-friendly without evidence, highlighting one green feature while ignoring a bigger harm, or using leafy imagery to imply a benefit that is not real.

Is greenwashing illegal in the UK?

Misleading environmental claims can break UK consumer protection law. Since 6 April 2025 the Digital Markets, Competition and Consumers Act 2024 has given the Competition and Markets Authority power to decide that a business has breached consumer law and to impose fines of up to 10 per cent of global turnover directly, without going to court. The CMA Green Claims Code sets out how to stay on the right side of the law.

What is the CMA Green Claims Code?

The Green Claims Code is guidance published by the Competition and Markets Authority in 2021 to help businesses make environmental claims that comply with consumer law. It sets six principles: claims must be truthful and accurate, clear and unambiguous, must not omit important information, must make fair comparisons, must consider the full life cycle of the product, and must be substantiated with evidence.

How can a business avoid greenwashing?

Be specific rather than vague, and hold evidence for every environmental claim before you publish it. Avoid unqualified words like green, eco-friendly or sustainable unless you can prove what they mean, make only fair like-for-like comparisons, consider the whole life cycle of the product, and be clear about any conditions. If you cannot substantiate a claim, do not make it.