California Climate Disclosure Alert: SB 253 Deadline Set for November 10, 2026

Large companies doing business in California now have a confirmed deadline for their first greenhouse gas emissions disclosures.

Here’s what’s changed, what’s next, and what to do about it.

What Is SB 253?

SB 253 is California’s Climate Corporate Data Accountability Act which requires large companies doing business in California to publicly disclose greenhouse gas (GHG) emissions across their entire value chain. The law is administered by the California Air Resources Board (CARB) and applies to both public and private U.S. companies with more than $1 billion in total global annual revenue. The Office of Administrative Law approved CARB’s regulation to implement SB 253 on August 31, 2026, with a September 1, 2026, effective date.

Key Deadlines to Watch

• November 10, 2026: First-year reporting deadline for Scope 1 (direct) and Scope 2 (purchased energy) emissions, covering 2025 fiscal year data. CARB has opened a voluntary intake platform for submissions. No third-party assurance is required for this first cycle.
• 2027: Scope 3 (value chain) reporting begins, initially limited to five priority categories, covering 2026 fiscal year data.
• 2027–2029:  Limited third-party assurance becomes mandatory for Scope 1 and 2 data.
• 2030: Assurance standards tighten further, and Scope 3 data enters limited assurance review.

Penalties and Fees

• Fines of up to $500,000 per reporting year for failing to report, reporting late, or violating requirements.
• A safe harbor through 2030 protects good-faith Scope 3 errors — but not a failure to file.
• A flat annual fee (currently $2,000–$7,000) applies to covered entities, with CARB invoices expected by December 10, 2026.

Where Things Stand on SB 261

SB 253’s companion law, SB 261, requires companies with over $500 million in annual revenue to disclose climate-related financial risks. Unlike SB 253, SB 261 remains on hold: the Ninth Circuit issued a temporary injunction pending appeal that prevent its implementation, and the issue of whether the Ninth Circuit should reverse the District Court’s decision and issue a preliminary injunction that prevents SB 261 implementation during the trial at the District Court is currently pending. SB 253 faces no such obstacle, a preliminary injunction request against it was denied and affirmed on appeal.

What Companies Should Do Now

• Confirm whether your company meets the $1 billion revenue threshold for SB 253.
• Start compiling Scope 1 and Scope 2 data now,  CARB has signaled it will accept data your company already collects for other purposes.
• Track SB 261 separately, since its applicability and timeline remain unsettled pending the Ninth Circuit’s ruling.
• Revisit your disclosure controls in light of the penalty exposure outlined above.

Questions? Contact us.

This summary is for informational purposes and does not constitute legal advice. Our attorneys regularly advise clients on SB 253 and SB 261 compliance, CARB rulemaking, and related litigation risk. If you have questions about how these requirements apply to your business, our team is just an email or phone call away.