CAP Code Section 11
For UK advertisers and agencies wondering how the ASA judges environmental claims, including net zero and carbon neutral wording. This page covers what you need to know and ways to avoid running into issues.
What we've seen reported
The CAP Code's Section 11 sets the UK advertising rules on environmental claims in non-broadcast ads, covering a clear basis for each claim, substantiation for absolute claims and the full life cycle, according to its text.1
Last updated October 2026 · General information only, not legal advice. Sources.
What the rules cover
These are the kinds of wording Section 11 of the CAP Code and CAP's guidance describe, according to their text, and how they tend to show up in UK ads.1,4
| Phrase or term | In practice |
|---|---|
| "Eco-friendly", "green", "kinder to the planet" | Rule 11.1: the basis of the claim made clear, as unqualified claims could mislead by omitting material information. |
| "Sustainable", "good for the planet" | Rule 11.3: absolute claims supported by a high level of substantiation. |
| "Greener", "friendlier" | Comparative claims, described as justifiable where there's a total environmental benefit and a clear basis. |
| "Environmentally friendly" product claims | Rule 11.4: based on the full life cycle unless the ad says otherwise, with its limits made clear. |
| "Carbon neutral", "net zero" | CAP guidance: avoid unqualified claims, and say whether they rely on offsetting or reductions. |
| "Net zero by 2035" | Future goals described in CAP guidance as needing a verifiable strategy behind them. |
| "Free from…" ingredient claims | Rule 11.7: no highlighting the absence of an ingredient not usually found in competing products. |
The ASA has already ruled against green claims under Section 11 of the CAP Code.
A clothing retailer's paid search ad calling its children's range "sustainable" was ruled misleading, with no evidence covering the full life cycle.
A baby products company's "eco" claims were ruled misleading because evidence of no harm over the products' full life cycle wasn't shown.
Where it goes wrong
One approved claim ends up in many channels, markets and languages. Along the way it gets shortened, translated and reworded, and some versions end up using the very phrases you are trying to avoid.
"Kora refill pouch uses 70% less plastic than our bottle."
How Arbitr helps
Read every version by hand? Or use AI to check what you publish against what you've already approved.
FAQ
In most of your marketing. The CAP Code covers non-broadcast marketing communications, including some non-paid-for ones from UK marketers, according to its scope,2 and we usually find green claims in:
Brief them with the approved wording and its qualification, not just the headline. CAP guidance says these claims should make clear whether they rely on offsetting,4 and that context is what tends to fall off in a six-second cut or a social caption. Ask for every cutdown back before it runs. Our brand compliance page shows how teams track this.
Rule 11.3 describes absolute claims as needing a high level of substantiation,1 so keep the evidence with the claim: the approved wording, the data and the part of the life cycle it covers, who approved it, and every ad it appears in. If the ASA asks, the record answers rather than an inbox.
How it applies to a specific claim is a question for your legal adviser. Where that claim appears across your markets and languages is a question Arbitr answers.
More than the brand team. Performance marketers write paid search copy, social teams post daily, and agencies and influencers create work in your name. A short briefing for each, built from examples in your own ads, lands better than a policy document. Rules in other markets are on our environmental claims hub.
They're separate but linked. The CAP Code is the advertising code the ASA applies, and its Section 11 says marketers should take account of the Green Claims Code published by the Competition and Markets Authority.1 More is on our CMA Green Claims Code page.
As an absolute claim, in several recent rulings. CAP's advice describes unqualified "sustainable" claims being understood to apply across a product's entire life cycle, so a high level of substantiation was needed.5
Arbitr checks your content against the rules, claims and terms your team has approved, and reports where something doesn't match, by channel, market and language. It reports matches against your rules, not legal verdicts. What to do with each one stays with your team.
