This guide is designed to help fashion and textile brands understand and navigate the UK Green Claims Code with clarity.
Whether you are a sustainability lead, compliance officer, or marketing decision-maker, this guide is intended to serve as a practical reference for aligning your sustainability narrative with regulatory expectations.
You would think that the UK Green Claims Code, a regulation that stops you from using unsubstantiated sustainability claims, would be the enemy of sustainable fashion. But it actually is an ally. By holding all brands to the same standard of honesty, it protects businesses that are genuinely investing in sustainability from being undercut by those who are merely claiming to.
The regulatory environment has now matured to the point where vague green language carries real legal and financial risk. The solution is to talk about it more precisely, more honestly, and with the evidence to back it up.
In this guide, we have tried to explain what the Code requires, why fashion brands are under particular scrutiny, what has happened to those who got it wrong, and how to market your sustainability credentials legally and confidently.
What is the Green Claims Code?
The UK Green Claims Code (GCC) is a regulatory framework established by the Competition and Markets Authority (CMA) UK to protect consumers from misleading environmental advertising, a practice commonly known as “greenwashing.”
It ensures that any claims that businesses make about their environmental impact, sustainability, or eco-friendliness are legally compliant under UK consumer protection law.
The 6 Principles of Green Claims Code
GCC sets out six principles that all businesses must follow when making environmental claims. These principles apply across every dimension of a brand’s communications: advertising, packaging, product names, website copy, social media, hang tags, and even the filters on your e-commerce site.
| # | Principle | What It Means | Non-Compliant Example | Compliant Approach | Key Risk |
| 1 | Claims Must Be Truthful and Accurate | Claims must reflect the actual environmental benefit with no exaggeration or overstatement. | Calling a T-shirt “organic” when only 10% of the fabric is organic cottonOr labeling packaging “recyclable” when parts are not. | Clearly state the exact percentage or component (e.g., “Contains 10% organic cotton”). | Misleading consumers about the true sustainability of a product. |
| 2 | Claims Must Be Clear and Unambiguous | Avoid vague, generic terms unless clearly defined and supported. | Using terms like “eco,” “green,” or “sustainable” without explanation.The CMA calls these claims ‘difficult to substantiate.’ | Use specific, measurable claims (e.g., “Made with 50% recycled polyester”). | Vague language that cannot be substantiated. |
| 3 | Claims Must Not Omit or Hide Important Information | You must not hide or ignore key details that change how a claim is understood. | Highlighting a recycled zip while the rest of the garment is non-sustainable. | Provide a balanced view of the product, including limitations. | “Misleading omission” under consumer law. |
| 4 | Comparisons Must Be Fair and Meaningful | Comparisons (either to older collections or competitors) must be based on clear, objective, and like-for-like metrics. | Saying a collection is “greener” without explaining compared to what or how. | Use quantified comparisons (e.g., “50% more recycled fibres than previous range”). | Unsubstantiated or unclear comparisons. |
| 5 | Claims Must Consider the Full Life Cycle | Claims should not mislead about the overall environmental impact of the product. | Calling a product “eco” based only on one aspect (e.g., organic cotton) while ignoring other impacts. | Use scoped claims (e.g., “Made with organic cotton sourced from certified farms”). | Overlooking major environmental impacts across the lifecycle. |
| 6 | Claims Must Be Substantiated | All claims must be backed by credible, up-to-date evidence. | Using eco labels without proof or authorisation; making claims without data. | Maintain documentation, certifications, and verifiable data. | Inability to prove claims during audits or investigations. |
All six principles apply together, and more than one, and often all of them, will be relevant to any given claim. Treat them as a unified framework.
The Cost of Getting it Wrong
Until recently, the CMA’s primary enforcement tools were court proceedings and formal undertakings. Both are serious, but slow and resource-intensive. That has changed.
The Digital Markets, Competition and Consumers Act 2024
The Digital Markets, Competition and Consumers Act 2024 changed the enforcement landscape for UK consumer protection law, including greenwashing. The new powers, which came into force in April 2025, allow the CMA to impose financial penalties without needing to go to court first.
- The CMA can now fine businesses up to 10% of global annual turnover for breaches of consumer protection law, including misleading environmental claims
- This applies to businesses of all sizes
- The CMA can also require businesses to pay compensation directly to affected consumers
- Enforcement can be faster and more targeted than under the previous court-only model
To illustrate the scale, for a fashion brand with £50 million in global annual revenue, a maximum fine under these powers would be £5 million. For a brand with £500 million in revenue, it would be £50 million.
Fashion Brands that Faced the Consequences
The fashion industry has been one of the CMA’s primary enforcement targets since the Green Claims Code was introduced. The regulator’s own review found that up to 40% of green claims made online were potentially misleading, and the fashion sector was cited as a major source of concern.
The Investigation into ASOS, Boohoo, and George at Asda
In July 2022, the CMA launched a formal investigation into three of the UK’s most prominent fashion retailers: ASOS, Boohoo, and George at Asda. The regulator’s concerns centred on how each brand marketed its ‘sustainable’ or ‘eco-friendly’ clothing collections.
The specific problems identified included:
- Using terms like ‘eco’, ‘responsible’, and ‘sustainable’ as collection labels without defining what those terms meant
- Failing to link individual products to specific, verifiable sustainability criteria
- Using generic ‘green’ imagery, like leaves, earth globes, and nature motifs, on products and pages where no substantiated environmental benefit existed
- Insufficient disclosure of the proportion of recycled or organic content in garments
In March 2024, all three retailers signed formal legal undertakings with the CMA. These are binding legal commitments and they require sweeping changes to how these brands communicate sustainability to consumers.
What the Undertakings Required
Under their undertakings, the three retailers committed to:
- Removing vague collection labels like ‘eco’ and ‘responsible’ unless they meet specific, clearly stated criteria
- Stating the exact percentage of recycled or organic fibres in individual garments
- Clearly defining the sustainability criteria for any collection that is marketed as green
- Removing misleading natural imagery from standard product listings
- Making sustainability information prominent and easily accessible to consumers
The Ripple Effect
The ASOS, Boohoo, and George at Asda cases were not isolated. In September 2024, the CMA sent warning letters to 17 additional well-known fashion brands, signalling that the entire sector was under scrutiny.
How to Market Sustainability Legally: A Practical Checklist for Brands
Brands that genuinely invest in sustainability should have no difficulty complying to GCC and compliant claims are likely to build more durable consumer trust than vague green language ever could.
Here is a practical starting point for reviewing your current communications:
1. Audit Your Website and Navigation
Review any sustainability-themed filters, banners, or collection labels on your e-commerce site. If you have a ‘Sustainable’ filter, question what precisely qualifies a product for inclusion? Is that criteria clearly disclosed to the consumer on the product page itself?
If the criteria are not defined and disclosed, the filter should be renamed or removed until they are. Consider replacing ‘Sustainable Collection’ with something specific. ‘Made with Recycled Materials’ or ‘Certified Organic Cotton’ are far less likely to attract regulatory attention.
2. Scrub Your Marketing Copy
Go through your product descriptions, campaign copy, social media captions, and email marketing with a fine-tooth comb. Flag every instance of the following words and ask whether they are substantiated:
- Eco / eco-friendly
- Sustainable / sustainability
- Natural
- Responsible
- Green
- Better for the planet
- Conscious
For each flagged term, either replace it with a specific, data-backed claim, or remove it entirely unless your evidence base is robust enough to defend it.
3. Review Your Imagery
Green leaves, earth globes, rainforest photographs, and recycling symbols all communicate environmental credentials implicitly, even without any text. Under the GCC, the visual presentation of a claim is part of the claim itself.
Remove or reconsider any environmental imagery from product listings, packaging, or campaigns where the product does not have a substantiated environmental benefit that justifies that imagery.
4. Make Information Accessible
Requiring a consumer to scan a QR code, click through three web pages, or find a footnote to discover the basis of an environmental claim is unlikely to be sufficient. Important qualifying information must be prominent and close to the main claim.
If you genuinely cannot fit all the necessary context into the primary claim, you may be able to provide a direct link to supporting information, but that information must be readily accessible, and must not contradict the main claim.
5. Ensure You Have Evidence Before You Publish
The legal obligation is to have substantiating evidence before the claim is made. Before any environmental claim goes live, your marketing and compliance teams should be able to answer the following questions:
- What specific environmental benefit does this claim relate to?
- What evidence supports this claim, and how recent is it?
- Does the evidence reflect the full product or service, or only part of it?
- Is this evidence publicly accessible, or can we make it so?
- Has it been independently verified, or is it self-assessed?
6. Keep Claims Under Review
Consumer expectations, scientific understanding, and regulatory guidance all evolve. A claim that was compliant two years ago may not be today. Build a regular review cycle into your compliance process, particularly for any long-running campaigns or evergreen product descriptions.
The History and Evolution of the Code (2020–2026)
| Year / Period | Milestone | What Happened |
| 2020–2021 | Global Review of Green Claims | The CMA and global regulators found ~40% of online green claims were misleading, prompting regulatory action. |
| Sept 2021 | Official Launch | The Green Claims Code was published, with a grace period until Jan 2022 for businesses to comply. |
| 2022–2023 | Industry Crackdown Begins | Focus on fashion and FMCG sectors known for greenwashing. |
| July 2022 | Fashion Investigation | CMA investigated ASOS, Boohoo, and George at Asda over vague sustainability claims. |
| Late 2023 | FMCG Expansion | Investigation into Unilever over recyclability claims and misleading imagery. |
| March 2024 | Landmark Fashion Ruling | ASOS, Boohoo, and Asda signed legal undertakings to standardise claims and improve transparency. |
| May 2024 | DMCC Act Passed | New law gave CMA direct enforcement powers without needing court proceedings. |
| April 2025 | Enforcement Powers Begin | CMA gained authority to fine companies up to 10% of global annual turnover. |
| Autumn 2025 | Aggressive Enforcement | Shift from guidance to active, large-scale enforcement of greenwashing rules. |
| Jan 2026 | Supply Chain Accountability | Brands made responsible for verifying environmental claims across entire supply chains. |
| 2026 (Current) | Multi-Regulator Enforcement | CMA works with FCA and ASA to enforce strict accountability across the UK market. |
Frequently Asked Questions (FAQs)
1. Who does the Green Claims Code apply to?
The Code applies to any business that markets or sells products to UK consumers, regardless of where the business is headquartered. This includes manufacturers, wholesalers, direct-to-consumer (DTC) brands, high-street retailers, and even influencers or affiliate marketers promoting products in the UK.
2. What are the penalties for violating the Green Claims Code?
Following the enforcement of the Digital Markets, Competition and Consumers (DMCC) Act in April 2025, the Competition and Markets Authority (CMA) was granted the power to directly fine non-compliant businesses up to 10% of their global annual turnover. Prior to this, the CMA had to take companies to court, but they can now act as the direct enforcer.
3. Can our brand still use words like “sustainable,” “eco-friendly,” or “conscious”?
Generally, not without immediate and prominent qualification. The CMA views broad, absolute terms like “eco-friendly,” “green,” or “conscious” as inherently misleading because they imply a product has no negative environmental impact whatsoever (which is virtually impossible in fashion and manufacturing). Instead, you must use specific, factual language, such as, “This t-shirt is made from 70% certified organic cotton.”
4. Does the Code apply to imagery and branding, or just written copy?
It applies to all forms of marketing, including visual branding. Using imagery like green leaves, earth globes, nature scenes, or recycling symbols on your packaging or website can be deemed a violation if the product itself does not have a substantiated, significant environmental benefit. Visuals must not imply a broader ecological benefit than the product actually delivers.
5. How do we properly “substantiate” our claims?
To substantiate a claim, your brand must hold credible, up-to-date, and objective evidence before the claim is published. This includes independent third-party certifications (e.g., GOTS for organic cotton, FSC for packaging), comprehensive supply chain audits, and life-cycle assessments. Consumers must also be able to easily access this information, usually via a direct link next to the claim.
6. What happens if our supplier lied to us about the materials being eco-friendly?
You are still liable. Under the CMA’s 2026 updated supply chain guidance, the brand making the claim to the consumer bears the ultimate responsibility. You cannot pass the blame to a third-party manufacturer. Brands are legally required to conduct rigorous due diligence and cannot simply take a supplier’s word for it.
7. Are there real-world examples of fashion brands being penalised?
Yes. The most prominent examples are ASOS, Boohoo, and George at Asda. Following a major CMA investigation, these brands were forced to sign formal legal undertakings in March 2024. They had to scrap vague “sustainable” collections, explicitly detail the exact percentages of recycled fibers in their products, and remove misleading environmental filters from their websites.
8. What is the difference between the CMA and the ASA regarding green claims?
The CMA (Competition and Markets Authority): Enforces consumer protection law across all business practices. They can issue massive fines and force companies to change their entire operational and marketing structures.
The ASA (Advertising Standards Authority): Regulates specific advertisements (TV, social media ads, billboards). The ASA uses the Green Claims Code to judge complaints and can order ads to be banned or taken down, but they do not have the power to levy the 10% global turnover fines that the CMA does.
9. Do we have to talk about the entire “life cycle” of a product?
Yes, if your claim implies an overall environmental benefit. If you claim a pair of shoes is “better for the planet,” you must consider the raw material extraction, manufacturing emissions, shipping, how long the shoe lasts, and whether it can actually be recycled at the end of its life. If it ends up in a landfill, calling it “eco-friendly” based solely on the fact that it uses recycled laces is a breach of the Code.
10. How can we audit our brand to ensure compliance?
The best first step is to review all consumer-facing touchpoints (product tags, website copy, social media ads, and drop-down search filters). Remove all vague terminology, ensure every environmental claim has a clear percentage or specific metric attached, verify that your supply chain evidence is up to date, and clearly link to your sustainability criteria so customers can easily read it. When in doubt, consult a legal compliance expert specializing in UK consumer law.
Sources & Further Reading
Official Guidance & Legislation
CMA Guidance on Environmental Claims on Goods and Services (CMA146) The primary source document underpinning this entire guide. Published 20 September 2021 by the CMA. https://www.gov.uk/government/publications/green-claims-code-making-environmental-claims
The Green Claims Code (Campaign Site) The CMA’s consumer-facing hub for the Code, including the six principles in summary form. https://greenclaims.campaign.gov.uk
Digital Markets, Competition and Consumers Act 2024 The legislation that gave the CMA direct fining powers of up to 10% of global turnover, in force from April 2025. https://www.legislation.gov.uk/ukpga/2024/13
Consumer Protection from Unfair Trading Regulations 2008 The underlying consumer protection law on which the Green Claims Code is based. https://www.legislation.gov.uk/uksi/2008/1277
Business Protection from Misleading Marketing Regulations 2008 Governs business-to-business environmental claims. https://www.legislation.gov.uk/uksi/2008/1276
CMA Enforcement Actions
CMA Fashion Greenwashing Investigation — ASOS, Boohoo & George at Asda Details of the investigation launched July 2022 and the legal undertakings accepted March 2024. https://www.gov.uk/cma-cases/greenwashing-in-the-fashion-sector
CMA Online Greenwashing Review (2021) The CMA’s sweep of online claims that found up to 40% of environmental claims could be misleading — a key trigger for fashion sector enforcement. https://www.gov.uk/government/news/cma-puts-businesses-on-notice-over-fake-green-claims
Advertising Standards
ASA & CAP Guidance on Environmental Claims The Advertising Standards Authority’s rules on green claims in advertising, which run alongside and complement the CMA’s Code. https://www.asa.org.uk/advice-online/environmental-claims.html
CAP Code (UK Code of Non-Broadcast Advertising) The advertising rulebook that incorporates environmental claims standards. https://www.asa.org.uk/codes-and-rulings/advertising-codes/non-broadcast-code.html
Further Reading
Advertising Standards Authority — Rulings on Green Claims A searchable database of ASA adjudications on misleading environmental advertising, useful for understanding how the rules apply in practice. https://www.asa.org.uk/rulings.html
ISO 14021 — Environmental Labels and Declarations The international standard for self-declared environmental claims, referenced by the CMA as a benchmark for substantiation. https://www.iso.org/standard/72092.html
Ellen MacArthur Foundation — Circular Economy in Fashion Background reading on lifecycle thinking and sustainable design principles, useful context for Principle 5 (full life cycle consideration). https://ellenmacarthurfoundation.org/topics/fashion/overview
This article is for informational purposes only and does not constitute legal or professional advice. Businesses should refer directly to the official GCC regulations or seek independent legal advice to confirm compliance. The authors of this guide or GreenStitch are not responsible for any actions taken based on its contents.
