Your Supplier's Green Claims Are Now Your Legal Liability — What the CMA's 2026 Guidance Means for UK Businesses

In January 2026, the UK Competition and Markets Authority (CMA) published new guidance that changes the stakes for every business using environmental claims in its marketing.

The headline: you can now be held liable for green claims you did not write.

If your brand says your products are made from sustainably sourced materials because a supplier told you so — that claim is yours to own. If a retailer stocks your product and promotes it as eco-friendly based on what your packaging says — that retailer is now in scope too.

The CMA's guidance, 'Making green claims: Getting it right, across the supply chain', published on 22 January 2026, closes what many businesses had treated as a gap: the assumption that liability for misleading environmental claims stops with whoever originated them. It does not.

For UK SMEs operating anywhere in a supply chain — whether you make products, source them, sell them, or market them — this guidance matters. Here is what changed, why the stakes are higher than they have ever been, and what you need to do about it.

What the CMA's January 2026 Guidance Actually Says

The new guidance builds on the original Green Claims Code, published in 2021, which set out six principles for making honest environmental claims to consumers. That earlier guidance focused primarily on the businesses making claims directly — the brand on the label, the retailer writing the product description.

The January 2026 guidance extends the responsibility significantly. Its core principle: any business that repeats, relies on, or passes on an environmental claim made by another party in the supply chain can be treated as making that claim themselves.

In practice, this means:

• A retailer promoting a supplier's product as 'carbon neutral' takes on responsibility for whether that claim is accurate — even if the claim originated with the manufacturer.

• A brand passing on a supplier's 'sustainably sourced' certification in its own marketing is accountable for verifying it, not just repeating it.

• An online marketplace displaying a seller's eco-credentials in product listings can be liable if those credentials are misleading.

• A distributor using supplier-provided environmental data in trade materials carries shared responsibility for the accuracy of that data.

The CMA is explicit: ignorance is not a defence. An unwitting breach is still a breach. Liability does not depend on intent.

Who This Applies to

The guidance applies to every actor in the supply chain: raw material suppliers, manufacturers, brands, distributors, retailers, and online marketplaces. There are no sector exemptions and no formal carve-outs for small businesses.

The CMA does acknowledge that 'reasonable steps' will look different depending on the size of the business, the significance of the claim being made, and what verification evidence is available. A small independent retailer stocking a product will not be expected to conduct the same depth of due diligence as a major supermarket group. But both are expected to do something — and to be able to demonstrate it.

How This Extends the Green Claims Code

The original Green Claims Code set six principles. Claims must be truthful and accurate. They must be clear and unambiguous. They must not omit important information. Comparisons must be fair. Claims must consider the full lifecycle of the product. Claims must be substantiated.

None of that has changed. What the January 2026 guidance does is apply those same principles to every business in the chain — not just the one whose name appears on the label. The substantiation requirement now cascades through the supply chain. You are responsible not only for what you say, but for what you repeat.

Why the Stakes are Higher Than They Were Before

The CMA has had the power to investigate misleading environmental claims for years. What has changed is the speed and severity of enforcement.

Under the Digital Markets, Competition and Consumers Act 2024 (DMCCA), which came into force in April 2025, the CMA no longer needs to take a business to court to impose financial penalties. It can now issue fines directly — without a judge — up to 10% of global annual turnover, or £300,000, whichever is higher.

That is a fundamental shift in enforcement risk. Previously, the CMA's path to penalty ran through the court system: slow, expensive, and uncertain for both parties. Most businesses could reasonably expect a warning, then time to fix the problem before any sanction. That operating assumption no longer holds.

Direct Fining Powers: What They Mean in Practice

Direct fining means the CMA can move faster, target more businesses simultaneously, and impose meaningful penalties without the friction of litigation. It also means that the threat of enforcement is now credible for smaller cases — not just large, high-profile greenwashing scandals.

The 10% of global turnover figure is the upper limit, not the default. For a first offence by a small business, fines are likely to be proportionate. But the guidance makes clear that the absence of internal processes for verifying environmental claims will be treated as an aggravating factor — meaning the fine will be higher for businesses that cannot demonstrate they tried to take compliance seriously.

What Counts as an Aggravating Factor

According to the guidance, businesses that lack documented procedures for approving, reviewing, and substantiating environmental claims face increased exposure. Specifically:

• No documented approval process for environmental claims is an aggravating factor.

• No evidence of verification steps taken before relying on supplier claims is an aggravating factor.

• Claims that have not been reviewed since they were first made are an aggravating factor.

• No escalation procedure when supplier evidence cannot be obtained is an aggravating factor.

The message is clear. Compliance is not just about whether the claim is accurate. It is also about whether you can show you took the issue seriously before something went wrong.

The Verification Problem — What 'Reasonable Steps' Actually Means

The phrase 'reasonable steps' carries a lot of weight in this guidance. The CMA has been careful not to define it too prescriptively, because what is reasonable for a multinational retailer is not the same as what is reasonable for an independent food producer. But the guidance does give clear direction on what it expects to see.

Reasonable steps include:

• Requesting underlying evidence — the data behind the claim, not just the claim itself or a certificate that says it is true.

• Maintaining documentation — a record of what evidence was reviewed, who assessed it, and when.

• Building ongoing review into your processes — environmental claims need to be re-checked as supply chains change, certifications expire, and standards evolve.

• Having an escalation path — a clear procedure for what happens when a supplier cannot or will not provide sufficient evidence.

A supplier certificate or a tick-box on a supplier questionnaire is unlikely to be sufficient for significant claims. The CMA expects businesses to look behind the certificate — to ask what it is based on, who issued it, and whether the audit process behind it is robust enough to justify the claim being made.

When You Cannot Get the Evidence

This is where the guidance gets uncomfortable for many businesses. If your supplier will not or cannot provide the evidence to substantiate a claim, the CMA's position is unambiguous: do not make the claim.

That creates a real practical problem for businesses that have built supplier sustainability credentials into their brand positioning. If those credentials cannot be substantiated, the guidance says they should be removed from marketing materials, appropriately qualified, or the trading relationship reconsidered.

'Reconsidered' is a significant word. The CMA is signalling that it expects businesses to treat the inability to verify a sustainability claim as a material issue in a commercial relationship — not just a compliance inconvenience to manage around.

What This Looks Like in Practice — CMA Worked Examples

The CMA published worked examples alongside the guidance. Two are particularly instructive for businesses operating in retail or branded goods.

Example One: The Supermarket and the Body Wash

A supermarket includes a brand's body wash in its 'environmental range', claiming all products in the range contain at least 60% organic content. The brand does not dispute the listing. In reality, the product contains only 10% organic ingredients.

The CMA's analysis: both the supermarket and the brand could face enforcement action. But enforcement is likely to focus on the supermarket — as the party that created the marketing claim and was best placed to verify it before placing products in the range.

The lesson for retailers: curating an 'eco range' or 'sustainable edit' creates direct exposure. You own the curation decision — which means you own the verification obligation that comes with it.

Example Two: The Eco-Friendly Cleaning Spray

A manufacturer labels a cleaning spray 'eco-friendly' when it contains chemicals harmful to the environment. A retailer stocks and promotes the product using the same 'eco-friendly' label in its own marketing materials.

Both are in scope. Neither can point to the other as the responsible party.

This example matters because the retailer did nothing except repeat what the manufacturer said — which is exactly the behaviour this guidance is designed to address. Passing on a claim without any verification is no longer a safe default.

What UK SMEs Need to Do Right Now

The CMA guidance is not retrospective in its publication, but enforcement can examine current practices at any time. If you are using supplier-derived environmental claims in your marketing today, the following steps are not optional.

1. Audit Your Current Environmental Claims

List every environmental claim that appears anywhere in your marketing: website, product pages, packaging, emails, social media, brochures, trade materials. For each one, answer three questions: Where did this claim come from? What evidence supports it? Who provided that evidence?

If you cannot answer those questions for any claim, you have an exposure that needs to be resolved before someone with direct fining powers asks about it.

2. Ask Suppliers for the Evidence, Not the Certificate

Eco-labels and certifications are a starting point, not an endpoint. For any claim that is prominent in your marketing — or that contributes to your sustainability positioning — ask your supplier for the underlying data. What was tested? When? By whom? What did the results actually show?

If a supplier cannot provide this, document the fact that you asked and what they said. That record matters if enforcement ever comes knocking.

3. Build a Documented Approval Process

Every environmental claim you publish should go through a sign-off process that is recorded. This does not need to be bureaucratic. A shared document or structured sign-off template will do the job. What it must capture: who approved the claim, what evidence they reviewed, when the approval was made, and when it is next due for review.

The absence of this process is treated as an aggravating factor under the guidance. Creating one is one of the most straightforward risk-reduction steps available to any business.

4. Qualify or Remove Claims You Cannot Substantiate

If you are using phrases like 'sustainably sourced', 'eco-friendly', 'low carbon', or 'responsibly made' without specific, verifiable evidence for each one, they need to come down or be qualified.

Qualified versions are more defensible and more credible. 'Our primary packaging supplier holds FSC certification' is a specific, verifiable claim. 'Sustainable packaging' is not. The more specific the claim, the easier it is to substantiate — and the harder it is to challenge.

5. Review Your Commercial Relationships

Where suppliers are making environmental claims that you rely on in your own marketing, and they are unwilling or unable to provide supporting evidence, you have a commercial decision to make. The guidance signals clearly that such relationships should be reviewed — not simply tolerated as a fact of doing business.

That may feel like a regulator overstepping into commercial territory. But the alternative — continuing to make claims you cannot substantiate — is now a directly enforceable liability with fines attached.

Frequently Asked Questions

Does this guidance apply to small businesses?

Yes. The guidance applies to all supply chain actors regardless of size. What counts as 'reasonable steps' for verification will be calibrated to your business scale and resources — but the obligation to take reasonable steps applies to everyone. There is no formal SME exemption.

What if my supplier's certification turned out to be inaccurate? Am I still liable?

Potentially, yes. The key question is whether you took reasonable steps to verify the claim before relying on it. If you did — and you can demonstrate that through documentation — it is a strong mitigating factor. If you simply accepted the supplier's word without any verification process, your exposure is greater.

What is the difference between the Green Claims Code and this new guidance?

The Green Claims Code (2021) set out principles for making honest environmental claims directly to consumers. The January 2026 guidance extends those principles to every actor in the supply chain — not just the business whose name appears on the label. It also reflects the CMA's new power to impose direct fines under the DMCCA 2024, which did not exist when the original Code was published.

Does this cover claims made on social media?

Yes. Environmental claims made on any marketing channel — including social media, email, online product listings, and paid advertising — are covered by consumer protection law and the Green Claims Code. Channel does not determine coverage.

What does 'reasonable steps' actually mean for a small business?

It depends on the significance of the claim and the resources available to you. For minor, low-prominence claims, basic supplier documentation may be sufficient. For claims that are central to your brand positioning or appear prominently in your marketing, the bar is higher. The key principle is proportionality — and documentation of whatever process you used.

Can I be fined even if I was not trying to mislead anyone?

Yes. The guidance is explicit that an unwitting breach is still a breach. Intent is relevant to the severity of enforcement response, but it does not determine whether a breach has occurred. This is why internal processes matter — they are the evidence that you took the issue seriously, even if something subsequently went wrong.

The CMA's January 2026 guidance does not create new law — but it makes clear that existing law applies to everyone in the supply chain, not just the businesses making environmental claims directly to consumers. For UK businesses using supplier-derived sustainability credentials in their marketing, the question is no longer whether the rules apply to you. It is whether you can demonstrate you have taken them seriously.

If you have been operating on the assumption that your supplier's certification protects you, it is time to revisit that assumption.

My Green Comms helps SMEs cut through sustainability regulation and communicate with credibility. If you're unsure whether your current claims stand up to scrutiny, get in touch — we'll tell you what we think.

This article is for informational purposes only and does not constitute legal advice. If you have concerns about your legal accountability for environmental claims, speak to a qualified solicitor.