California AB 1305 (2023), Health and Safety Code §§ 44475-44475.3
For companies making carbon neutral claims in California working out what they have to disclose on their website. This page covers what you need to know and ways to avoid running into issues.
What we've seen reported
California AB 1305, the Voluntary Carbon Market Disclosures Act, calls for website disclosures behind net zero, carbon neutral and similar emissions claims made in California, and from businesses selling or using voluntary carbon offsets there.1,2
Last updated October 2026 · General information only, not legal advice. Sources.
What the rules cover
These are the kinds of wording California AB 1305 describes, according to its text, and the website disclosures each one is tied to.1,2
| Phrase or term | In practice |
|---|---|
| "Carbon neutral" | Claims about an entity or product made in California: website disclosures on how the claim was found to be accurate. |
| "Net zero emissions" | Disclosures on how interim progress toward the goal is measured, including any science-based targets. |
| "Significant reductions" in emissions | Claims of significant cuts to carbon dioxide or greenhouse gas emissions are named in the text too. |
| "Doesn't add carbon to the climate" | Claims implying no net addition of carbon dioxide or greenhouse gases are covered as well. |
| "Offset with verified carbon credits" | Entities using offsets: the seller, registry, project ID, project type and protocol behind them. |
| "Independently verified" | Disclosures say whether a third party has verified the company data and claims. |
| Carbon offsets sold in California | Sellers: project details, accountability if a project falls short, and data to check the credits. |
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.
"Our California operations run on 100% renewable electricity. See our climate disclosures."
How Arbitr helps
Read every version by hand? Or use AI to check what you publish against what you've already approved.
FAQ
In more places than most teams expect. California AB 1305 ties website disclosures to claims made in the state,1 and we usually find neutrality and net zero wording in:
Start from one approved list of climate claims and link each to its disclosure page. When marketing adds a new line, such as a product described as carbon neutral, check whether the disclosure covers it before it goes live. Our brand compliance page shows how teams track claims across channels.
Keep the approved wording, the offsets or data behind it, the disclosure page it points to, when that page was last updated, who approved the claim and where it's published. AB 1305 has disclosures updated at least once a year, according to its text,1 so the date matters.
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.
Sustainability and legal usually own it, but marketing, product, investor relations, sales and agency teams all write climate claims. A short briefing using your own claims helps. Related rules, such as the FTC Green Guides and the EU generic claims rules, are on our environmental claims hub.
According to its text, a civil penalty of up to $2,500 a day for each violation, capped at $500,000, in actions brought by the Attorney General, a district attorney, county counsel or city attorney.1
Most companies do, and it works for the file it reviews, in the language it reviews, before a campaign ships. It doesn't cover what's published afterwards: the market versions, the agency reworks, the sales deck built from the campaign six months later. That's a volume problem, not a failure of your legal team.
