UK Greenwashing Laws: CMA Green Claims Code Explained
UK Greenwashing Laws: CMA Green Claims Code Explained
Last updated: 24 June 2026 | Author: VerdaScope Editorial Team
The green claims code UK businesses most often need is the Competition and Markets Authority’s Green Claims Code, published in September 2021. It explains how existing consumer protection law applies to environmental marketing. UK greenwashing regulation is not a standalone “greenwashing act”—misleading green claims are enforced under the Consumer Protection from Unfair Trading Regulations 2008 (CPRs), the Business Protection from Misleading Marketing Regulations 2008 (BPRs), and advertising codes administered by the Advertising Standards Authority (ASA). CMA greenwashing investigations and ASA greenwashing rulings have increased, making this guide essential for marketers, compliance teams, and sustainability leads.
For the broader definition of greenwashing, see what is greenwashing. For prevention workflows, see how to avoid greenwashing.
Status Summary (June 2026)
| Item | Detail |
|---|---|
| Green Claims Code published | 20 September 2021 |
| Legal basis | CPRs 2008; BPRs 2008; ASA CAP/BCAP Codes |
| Primary enforcers | CMA, Trading Standards, ASA |
| Recent enforcement theme | Fashion green claims (ASOS, Boohoo, George at Asda undertakings, March 2024) |
| Code status | Guidance on existing law—not new legislation |
This page summarises guidance and law as understood in June 2026. It is not legal advice.
Direct Answer
The UK Green Claims Code is CMA guidance setting out six principles for environmental claims: truthful and accurate; clear and unambiguous; no omission of important information; fair and meaningful comparisons; full life-cycle consideration; and substantiation. Businesses making claims to UK consumers should comply with these principles under the CPRs. The ASA applies aligned standards to advertising. Breaches can lead to CMA court action, undertakings, ASA rulings, and consumer redress.
Key Takeaways
- The green claims code translates consumer law into practical principles—it does not replace legal advice or sector-specific rules.
- Competition and Markets Authority environment work includes sector reviews, investigations, and court enforcement for misleading claims.
- ASA greenwashing enforcement uses the CAP Code; the CMA may refer advertising cases to the ASA.
- Retailers and marketplaces can be liable for manufacturer claims on products they sell.
- Document substantiation before claims go live—not after a complaint.
- EU exporters face additional rules; see EU Green Claims Directive.
What Is the CMA Green Claims Code?
The CMA published Making environmental claims on goods and services in September 2021 following a sector-wide review of environmental claims. The review indicated that a high proportion of green claims could mislead consumers—prompting guidance and subsequent enforcement.
The code’s purpose is to help businesses:
- understand existing consumer protection law obligations;
- make claims that help consumers make informed choices; and
- avoid unfair competition against genuinely greener products.
The CMA is clear: the guidance is not legal advice, and only courts can definitively interpret the law. However, businesses that ignore the principles are more likely to attract CMA attention.
What counts as an environmental claim?
The CMA defines environmental claims as those suggesting a product, service, process, brand, or business:
- has a positive environmental impact or no impact;
- is less damaging than a previous version; or
- is less damaging than competing goods or services.
Claims can be explicit or implicit—including imagery, colours, logos, packaging, product names, and silence about material impacts. The code also notes relevance to wider sustainability claims.
The Six Principles of the Green Claims Code
1. Claims must be truthful and accurate
Claims must not mislead, even if partially true. Broad terms like “green,” “sustainable,” or “eco-friendly” imply positive or neutral overall impact unless the business can prove it.
CMA example: Labelling jeans “organic” when only 35% of material is organic cotton is likely misleading; consumers generally understand “organic” to mean the product is overwhelmingly organic.
2. Claims must be clear and unambiguous
Terms must match what consumers understand. Vague claims confuse decision-making and are hard to substantiate.
CMA example: A product labelled “recyclable” without clarifying whether that means packaging only—or the whole product—can mislead if only packaging is recyclable.
3. Claims must not omit or hide important relevant information
Cherry-picking benefits while ignoring significant negatives is a misleading omission.
CMA example: Soup marketed as “better for the environment” based on ingredients alone may mislead if packaging is non-recyclable plastic and that is not disclosed.
Carbon claims: Net zero or carbon-neutral claims should clarify reductions vs offsets and avoid implying products generate no emissions when they still do.
4. Comparisons must be fair and meaningful
Comparisons must be like-for-like, use the same methods, and cover important features consumers would consider.
5. Claims must consider the full life cycle
Businesses should think about environmental impact across the product life cycle—sourcing, manufacture, distribution, use, disposal—not only one stage.
6. Claims must be substantiated
Hold robust, credible evidence before making claims. Evidence must support the impression consumers receive, not only the literal wording.
UK Legal Framework Behind the Code
| Instrument | Who it protects | Relevance to green claims |
|---|---|---|
| CPRs 2008 | Consumers | Prohibits unfair commercial practices; misleading actions and omissions |
| BPRs 2008 | Businesses | Prohibits misleading advertising and comparative advertising B2B |
| CAP Code | Consumers (ads) | ASA enforces rules on misleading and environmental claims |
| BCAP Code | Consumers (broadcast) | Broadcast advertising standards |
The CMA shares consumer enforcement powers with Trading Standards Services and sector regulators. It also coordinates with the ASA—the CMA has stated it may refer advertising issues to the ASA instead of taking its own action.
Who must comply?
- Manufacturers, wholesalers, distributors, and retailers making claims to UK consumers
- Online marketplaces hosting third-party sellers (especially if curated as “eco” platforms)
- Businesses marketing to other businesses (BPRs; CMA urges high standards for SME buyers)
- Overseas firms selling to UK consumers
Possible consequences
- CMA or Trading Standards court proceedings
- Undertakings (legally binding commitments to change practices)
- ASA rulings—ads must be withdrawn or amended; adverse publicity
- Consumer redress in some circumstances
- Reputational and commercial fallout (contract loss, delisting)
CMA Greenwashing Enforcement: What Businesses Should Know
CMA greenwashing activity includes:
- Sector reviews (e.g. fashion, heating/installation products)
- Investigations into specific firms
- Guidance updates and open letters to sectors
- Court enforcement where undertakings are not agreed or breaches continue
Fashion sector case (illustrative)
The CMA’s investigation into ASOS, Boohoo, and George at Asda (from July 2022) resulted in undertakings in March 2024 covering claim accuracy, fabric specificity, collection criteria, filters, imagery, targets, and accreditation statements. The CMA issued an open letter to the wider fashion sector. Details are in greenwashing in fashion.
The CMA emphasised undertakings were without admission of wrongdoing.
ASA greenwashing
The ASA investigates complaints about ads including:
- “Green” energy tariffs
- Recyclability and biodegradability
- Carbon reduction claims
- Automotive emissions
ASA rulings are published and often require claim changes across websites and paid media. Marketers should treat ASA precedent as part of UK greenwashing regulation risk analysis.
Compliance Checklist: Green Claims Code UK
Before making a claim
- Identify the exact claim (including imagery and implied messages)
- Map claim to CMA principles (all six)
- Confirm sector-specific rules (food, textiles, energy labelling, etc.)
- Gather substantiation; record methodology and date
- Check comparisons are fair and like-for-like
- Assess life-cycle impacts; disclose material negatives or narrow claim scope
- Legal/compliance sign-off documented
At point of sale / in ad
- Plain language; key caveats prominent (not hidden small print)
- Qualifications close to main claim; not contradictory
- Third-party logos used only with correct scope
- QR/link to further detail where space is limited
Ongoing
- Review claims when products, suppliers, or law change
- Train agencies and marketplaces on approved claims
- Monitor CMA, ASA, and sector cases
- Log complaints and update substantiation files
Compliant vs Risky Approaches
| Topic | Risky | More compliant |
|---|---|---|
| General terms | “Eco-friendly product” | “Made with 80% recycled aluminium; see disposal guide” |
| Recyclability | “Fully recyclable” (mixed materials) | “Card sleeve widely recyclable in UK kerbside; film not recyclable” |
| Comparisons | “Greener than before” (undefined baseline) | “12% lower Scope 1+2 emissions vs 2023 baseline (method: [X])” |
| Offsets | “Carbon neutral product” | “Residual emissions offset via [scheme]; we reduced manufacturing emissions 8% in 2025” |
| Legal compliance | “Microbead-free shower gel” (post-ban) | Focus on genuine differentiators above legal minimum |
| Imagery | Green leaves on standard product | Imagery matches verified attribute; certification explained |
ASA and CAP Code: What Marketers Should Read
Environmental claims in advertisements fall under Section 11 of the CAP Code (environmental claims) and general misleading advertising rules. Practical ASA themes relevant to ASA greenwashing cases include:
- Qualification: Small print must not contradict the headline claim
- Scientific evidence: Absolute claims need a high standard of proof
- Visual imagery: Nature scenes can contribute to a misleading impression if unrelated to product attributes
Marketers should search the ASA rulings database for their sector before approving campaigns. A upheld complaint typically requires rapid multi-channel remediation—not only pulling one ad.
Relationship to Other UK and EU Rules
The Green Claims Code does not replace:
- Product-specific labelling (e.g. energy labels, textile fibre content rules)
- Financial promotions (FCA rules for investment products—see greenwashing in ESG investing)
- EU requirements for exports—see EU Green Claims Directive
Businesses must comply with all applicable layers.
Trading Standards and Local Enforcement
While the CMA leads high-profile cases, Trading Standards Services enforce the CPRs locally. SMEs sometimes assume only the CMA matters nationally; in practice, local authority Trading Standards can investigate complaints about packaging and advertising. Primary Authority partnerships (where eligible) let businesses get assured advice from a lead Trading Standards authority—worth considering if environmental claims are central to your value proposition.
Documenting Substantiation: What “Robust” Means
The CMA does not prescribe a single evidence format, but substantiation should be:
- Relevant to the specific claim and product
- Representative of current production (not outdated batch tests)
- Understandable to someone reviewing the claim without insider knowledge
- Complete enough to support the overall impression, including visual presentation
| Claim type | Typical evidence types |
|---|---|
| Recycled content | Supplier certificates, chain-of-custody, periodic testing |
| Recyclability | Waste industry guidance, recycling infrastructure assessment for UK |
| Carbon / emissions | GHG inventory, methodology document, verifier statement if used |
| Compostability | Standard test results (e.g. EN standards), disposal conditions |
| Comparative “greener” | Side-by-side LCA or metric with identical boundaries |
Keep evidence where you can produce it promptly if challenged.
Common Mistakes
- Treating the code as optional because it is “guidance”
- Relying on agency copy without substantiation files
- Assuming B2B claims are unregulated
- Using future targets as current achievements
- Ignoring marketplace listings and retailer templates
- Failing to update claims after reformulation or supplier change
Frequently Asked Questions
What is the green claims code UK?
It is CMA guidance (September 2021) on making environmental claims under existing UK consumer protection law, organised around six principles.
Is the Green Claims Code law?
The code itself is guidance. The underlying law includes the CPRs and BPRs. Following the code reduces risk of breaching those laws.
What is CMA greenwashing enforcement?
The CMA investigates misleading environmental claims, may secure undertakings or take court action, and publishes sector guidance. Trading Standards also enforces CPRs.
How does ASA greenwashing enforcement work?
Consumers and competitors can complain to the ASA. If ads breach the CAP Code, the ASA requires amendments and publishes rulings.
What are misleading green claims?
Claims that deceive consumers about environmental impact—through false statements, vague language, misleading presentation, or omission of material information.
Do small UK businesses need to comply?
Yes, if they make environmental claims to consumers. Trading Standards enforces consumer law locally.
How does this relate to the EU Green Claims Directive?
The EU proposal (March 2023) may impose substantiation and verification requirements for exports to the EU. UK domestic law already requires substantiation under CMA principles.
Does the Green Claims Code apply to Northern Ireland?
Yes. The CMA states the code applies across the UK, including Northern Ireland, subject to any future divergence between UK and EU laws that may require guidance updates.
Can we use the CMA checklist without reading the full guidance?
The CMA publishes a shorter checklist alongside the full code. Use it as a starting point, but complex claims (carbon, comparatives, multi-material packaging) usually require the full principles and legal advice.
Quick Reference: Six Principles on One Page
Print this for campaign briefs:
- Truthful — factually correct; not exaggerated
- Clear — ordinary consumer understands terms
- Complete — material negatives not hidden
- Fair compare — like-for-like, same methodology
- Life cycle — think beyond one attribute
- Substantiated — evidence ready before launch
If any box fails, stop the claim.
Sources and Update Log
| Date | Update |
|---|---|
| September 2021 | CMA publishes Green Claims Code |
| July 2022 | CMA opens ASOS, Boohoo, Asda fashion investigation |
| March 2024 | CMA announces fashion undertakings and sector open letter |
| June 2026 | This article reviewed |
Primary sources
- Competition and Markets Authority, Making environmental claims on goods and services, September 2021 — gov.uk
- Consumer Protection from Unfair Trading Regulations 2008
- Business Protection from Misleading Marketing Regulations 2008
- Committee of Advertising Practice (CAP) Code
- CMA misleading environmental claims case collection — gov.uk
Next Steps
- Definitions and examples → What is greenwashing
- Seven claim patterns → Types of greenwashing
- Implementation guide → How to avoid greenwashing
- Marketing teams → Making legitimate green marketing claims
- EU exports → EU Green Claims Directive