On June 24, 2026, the California Air Resources Board (CARB) gave companies three more months to file their first greenhouse gas emissions reports under SB 253, the Climate Corporate Data Accountability Act. The deadline for initial Scope 1 and Scope 2 reports moved from August 10 to November 10, 2026.
The extension is welcome, but it is not a reprieve. If your company is in scope and has been collecting emissions data, the report is due November 10.
Who is covered
SB 253 applies to U.S. entities with more than $1 billion in total annual revenue that do business in California. Revenue is measured company-wide, not just California sales, and “doing business” in California is a low bar — sales, property, or payroll in the state above modest thresholds can be enough. Private companies are covered on the same terms as public ones.
What the first report requires
| Item | 2026 (first report) | Later years |
|---|---|---|
| Scope 1 & 2 emissions | Required, for the prior fiscal year | Annual |
| Scope 3 emissions | Not required | Begins in 2027, subject to further CARB rulemaking |
| Third-party assurance | CARB has said it will not require assurance for the first reports | Assurance requirements phase in, with reasonable assurance for Scope 1 & 2 from 2030 |
The good-faith letter option
CARB has carried forward its first-year accommodation. Companies that were not collecting emissions data as of December 5, 2024 are not expected to submit Scope 1 and 2 data this year. Instead, they can file a statement on company letterhead confirming that fact. CARB has also signaled flexibility on format for first-year reports filed in good faith.
Where SB 261 stands
SB 261 — the companion law requiring biennial climate-related financial risk reports from companies with more than $500 million in revenue — remains stayed by the Ninth Circuit while the appeal challenging both laws is pending. The court heard argument in January 2026. A decision could lift the stay on SB 261, or affect SB 253 as well, so companies in scope for either law should keep their preparation on track.
What to do now
- Confirm applicability. Test revenue and California nexus at the right entity level, including parent and subsidiary structure.
- Choose your path for 2026. Either finalize Scope 1 & 2 data for the prior fiscal year or prepare the good-faith letter, with the decision documented.
- Assign ownership. Name who signs off on the report and how the board is briefed. Disclosure risk is a governance question, not just a sustainability one.
- Start Scope 3 scoping. Value chain data takes the longest to collect. Map your largest categories and supplier data sources before 2027.
- Watch the Ninth Circuit and CARB. CARB has proposed clarifying amendments, and the appeal could change the landscape quickly.
Southshore Partners helps companies assess applicability, build reporting programs, and put the right governance around them. Learn about our ESG practice or get in touch.
Jeff McCourt is the founder of Southshore Partners and a former CPG founder and CEO who led his company to B Corp certification.
This article is for general information only and is not legal advice. It reflects developments through early October 2026; rules and litigation in this area are changing quickly.