What is the Green Claims Code?

Quick Answer: The Green Claims Code is a set of principles published by the UK's Competition and Markets Authority (CMA) in September 2021 to help businesses make environmental claims that are honest, accurate, and legally compliant. It sets out six criteria that any green claim must meet, and sits within the broader framework of UK consumer protection law. Businesses that make misleading environmental claims risk enforcement action from the CMA, which since April 2025 has the power to fine companies directly, or from the Advertising Standards Authority (ASA).

What Is the CMA's Green Claims Code?

The Green Claims Code is guidance issued by the Competition and Markets Authority (CMA) to help UK businesses understand their legal obligations when making environmental claims about their products, services, or operations.

A green claim is any statement, label, or image that suggests a product, service, or business is better for the environment. This includes explicit statements like "made from 100% recycled materials" and implicit signals like green leaf imagery or the word "eco-friendly" on packaging.

The Code does not create new law. It clarifies how existing consumer protection legislation applies to environmental marketing. Since 6 April 2025, the primary legislation covering unfair commercial practices in the UK is the Digital Markets, Competition and Consumers Act 2024 (DMCCA), which replaced the earlier Consumer Protection from Unfair Trading Regulations 2008 for this purpose. This matters beyond a legal technicality: the DMCCA gives the CMA substantial new powers, covered in more detail below.

What Are the Six Principles of the Green Claims Code?

The Code sets out six criteria that every green claim must satisfy:

1. Be truthful and accurate. The claim must reflect the actual environmental performance of the product or business. Overstating benefits, even through vague language like "sustainable" or "green," is likely to mislead.
2. Be clear and unambiguous. The meaning of the claim must be immediately obvious to the average consumer. If a claim applies only to part of a product (for example, the outer packaging but not the inner), that must be stated clearly.
3. Not omit or hide important information. Businesses must not cherry-pick positive environmental aspects while concealing significant negative ones. A product's full environmental impact, across its life cycle, is relevant context.
4. Only make fair and meaningful comparisons. Any comparison with a competitor or a previous version of the product must be like-for-like. Comparisons must be based on the same scope, methodology, and time period.
5. Consider the full life cycle of the product or service. Claims must account for the environmental impact of a product from raw material extraction through to disposal, not just the stage that reflects most favourably on the business.
6. Be substantiated. Businesses must support every claim with credible, verifiable evidence. Businesses should be able to produce that evidence if challenged.

These principles closely mirror the CAP and BCAP Codes that the Advertising Standards Authority enforces, which is why a claim that falls foul of the Green Claims Code is often also an ASA risk.

Why Does the Green Claims Code Matter for Carbon Claims?

Carbon-related claims face the most scrutiny under the Code. Statements like "carbon neutral," "net zero," or "we've reduced our emissions by 50%" all qualify as explicit environmental claims and must meet all six criteria, and the difference between those terms is itself a common source of misleading claims.

This is where carbon accounting becomes directly relevant. A business cannot credibly claim to have reduced its carbon footprint, achieved net zero, or cut emissions by a specific percentage without a verified, methodology-aligned carbon footprint to reference, an approach Seedling's guide to carbon reduction vs offsetting covers in more detail. Without that baseline, the claim has no substantiation. A validated SBTi target is one of the strongest forms of evidence a business can point to, since it has already been independently checked against a recognised methodology.

The CMA has already taken enforcement action in this area. In March 2024, it resolved a long-running investigation into ASOS, Boohoo, and George at Asda by securing legally binding undertakings from all three retailers to use only accurate, clearly substantiated green claims, without making a formal finding of infringement. The CMA has also investigated boiler manufacturer Worcester Bosch and consumer goods group Unilever over similar concerns. Separately in the Netherlands, H&M discontinued its long-running "Conscious Choice" collection in 2025 after the Dutch Authority for Consumers and Markets found its claims relied on vague, unsubstantiated language, with H&M donating €500,000 to sustainability organisations as part of the resolution.

Since 6 April 2025, the stakes for UK businesses have risen sharply. The DMCCA gives the CMA the power to investigate and fine companies directly, without going through the courts, up to 10% of global annual turnover or £300,000, whichever is greater. This removes a significant procedural barrier that previously slowed enforcement, and the CMA has signalled that green claims remain a priority area under its new powers.

For businesses that want to make carbon claims with confidence, the starting point is a full-scope carbon footprint measured against a recognised standard, such as the GHG Protocol. Seedling produces GHG Protocol-aligned footprints covering Scopes 1, 2, and 3, with a clear audit trail of assumptions, data sources, and emissions factors, giving businesses the documented evidence base the Code requires.

How Does the Green Claims Code Relate to EU Green Claims Rules?

The UK's Green Claims Code is guidance, not legislation. The EU has taken a more legislative approach, though its path has been more complicated than it might first appear.

The EU's proposed Green Claims Directive, introduced by the European Commission in March 2023, would go further than the UK's approach, requiring businesses to have an accredited third party independently verify their environmental claims before making them public. In June 2025, the European Commission announced its intention to withdraw the proposal, and trilogue negotiations were subsequently cancelled, following concerns from within the European Parliament about the administrative burden on smaller businesses. However, the proposal has not been formally withdrawn, and its legal status remains unresolved.

That is not the full picture, though. A separate EU directive, the Empowering Consumers for the Green Transition Directive (Directive 2024/825), was adopted independently of the Green Claims Directive back in 2024 and is unaffected by its uncertain fate. It strengthens the EU's existing anti-greenwashing consumer protection framework and applies across all Member States from 27 September 2026. Among other things, it bans generic environmental claims like "eco-friendly" or "green" unless backed by recognised excellent environmental performance, and specifically targets "climate neutral" or similar claims based on offsetting rather than genuine emissions reductions, a topic covered from a UK perspective in Seedling's guide to the SBTi Corporate Net-Zero Standard.

UK businesses that trade in EU markets, or that anticipate tighter domestic regulation, should treat the Green Claims Code as a floor, not a ceiling. Scrutiny of environmental claims is increasing on both sides of the Channel, and with the Empowering Consumers Directive taking effect in the EU within months and the CMA's new direct fining powers already active in the UK, the standard of evidence required to support carbon and sustainability claims is rising quickly on both fronts.

What Counts as a Misleading Green Claim?

The Code identifies several patterns that are likely to constitute greenwashing:

• Vague or generic language such as "eco-friendly," "green," or "sustainable" without specific, verifiable evidence to support it
• Selective disclosure that highlights one positive environmental attribute while omitting significant negative impacts elsewhere in the product's life cycle
• Unqualified comparisons that claim a product is "greener" than a competitor without specifying the scope, methodology, or baseline used
• Claims based solely on offsetting, where a business claims carbon neutrality through offset purchases without first reducing its own emissions, rather than pairing credible offsetting, such as Woodland Carbon Code or Peatland Code credits, with genuine reductions
• Visual greenwashing, where imagery (green colours, leaf icons, nature photography) creates an impression of environmental benefit that the product's actual performance does not support

The European Commission's own 2020 study found that 53% of green claims examined in the EU gave vague, misleading, or unfounded information, and 40% had no supporting evidence at all. The UK picture is comparable.

What Does Compliance With the Green Claims Code Look Like in Practice?

Compliance is not a one-time exercise. It requires businesses to maintain the evidence behind every claim they make, and to update that evidence as their products and operations change.

In practice, this means:

• Measuring your carbon footprint to a recognised standard before making any carbon-related claim
• Documenting the methodology, data sources, and assumptions behind that measurement
• Making claims specific and scoped (for example, "we reduced Scope 1 and 2 emissions by 18% between 2022 and 2024" rather than "we're going green")
• Reviewing claims annually as you refresh your footprint data
• Keeping records that you could produce to the CMA or ASA if a claim is challenged

The businesses most exposed to enforcement risk are those making broad, unqualified claims without a documented evidence base, a risk that has grown materially now the CMA can fine directly rather than pursuing court action. The businesses best positioned to make credible green claims are those that treat carbon measurement as an ongoing process rather than a one-off project.

As regulatory expectations continue to rise on both sides of the Channel, the gap between businesses with well-documented carbon data and those without it will become increasingly visible, and increasingly costly to ignore.