Key Points

• California SB 253 requires large companies doing business in the state to report their Scope 1 and Scope 2 greenhouse gas emissions by November 10, 2026.
• Scope 3 emissions reporting and third-party assurance are expected to begin in 2027, so companies should start preparing now.
• The SB 261 climate risk reporting requirement is paused pending appeal, not invalidated, so companies should be ready to publish their reports.

If your company earns more than $1 billion a year and does business in California, your first emissions report under SB 253 is due to the California Air Resources Board (CARB) on November 10, 2026, which is less than a month away.

The law reaches public and private companies alike, including U.S. subsidiaries of foreign parents, and it counts revenue from all sources, not just California sales. By the deadline, covered companies must report their Scope 1 and Scope 2 greenhouse gas emissions.

Multinationals, private equity–backed groups and companies with multiple subsidiaries should confirm now which entities are covered.

On October 12, 2026, after a year of rulemaking that included several rounds of revisions and public comment, California's Office of Administrative Law approved CARB's implementing regulation, which took effect immediately and confirms the November 10 deadline and the first-year reporting options described below. For a fuller discussion of the underlying and related statute, see our prior alert here.

Below is a brief refresher on where things stand and what to do before the deadline.

The Laws in Brief

California's two climate disclosure statutes, enacted in 2023 and amended by SB 219 in 2024, apply to U.S. companies, public and private, that do business in California, based on total annual revenue.

Importantly, the revenue thresholds are not limited to California revenue. CARB counts a company's total gross receipts, regardless of whether the revenue was generated in California; California sales are relevant only to whether the company is "doing business" in the state.

CARB also determines applicability entity by entity, and reports under both laws may be consolidated at the parent-company level.

Under the Climate Corporate Data Accountability Act (SB 253) covered companies must submit their Scope 1 and Scope 2 greenhouse gas emissions to CARB by November 10, 2026. Reports may be filed through CARB’s online portal or by email to climatedisclosure@arb.ca.gov.

• SB 253 covers companies with more than $1 billion in annual revenue. It requires an annual disclosure of greenhouse gas emissions measured under the GHG Protocol. Scope 1 and Scope 2 emissions are due by November 10, 2026, and annually thereafter; Scope 3 reporting is expected to begin in 2027. Penalties may reach $500,000 per reporting year.
• SB 261 covers companies with more than $500 million in annual revenue. It requires a climate-related financial risk report, prepared under the TCFD framework or an equivalent standard such as ISSB, to be posted on the company's website every two years. Penalties may reach $50,000 per reporting year. SB 261 is currently stayed by the Ninth Circuit pending appeal. However, companies should be prepared as obligations under SB 261 could resume on short notice if the stay is lifted.

SB 253 and First-Year Flexibility

• No Scope 3 in 2026. Scope 3 reporting is expected to begin in 2027.
• Existing reports are acceptable. Companies that had, or were collecting, Scope 1 and Scope 2 data on or before December 5, 2024, may submit that data in one of three forms: an existing annual report, a report previously prepared for another program or voluntary initiative, or CARB’s template.
• Non-collection statement. Companies that did not possess and were not collecting Scope 1 and or Scope 2 data on or before December 5, 2024, may instead submit a statement on company letterhead explaining why they are not submitting a report.
• Which fiscal year to report. To give each company at least six months to compile data, most companies, including those that use the calendar year, should report data for the fiscal year that ended in 2025, though they may choose to report a more recent completed fiscal year if the data is available. Companies whose fiscal year ends on or before February 1 should report the fiscal year that ended in early 2026.

Takeaways

File by November 10, 2026
Confirm which entities in your corporate group are covered, and submit the Scope 1 and Scope 2 emissions data you already have to CARB before the deadline. If your company had no emissions data and was not collecting it as of December 5, 2024, you may instead submit a statement on company letterhead explaining why you are not filing a report.

Prepare Now for 2027
Independent third-party assurance and supply-chain (Scope 3) emissions reporting are expected to begin in 2027. Because capacity among qualified assurance providers is limited, engage a provider early and begin collecting supplier data now.

Continue Preparing for SB 261
The SB 261 climate-related financial risk report requirement is only paused pending appeal and has not been invalidated. Keep your report substantially complete so you can publish promptly if the stay is lifted.

This information is intended to inform firm clients and friends about legal developments, including the decisions of courts and administrative bodies. Nothing in this alert should be construed as legal advice or a legal opinion. Readers should not act upon the information contained in this alert without seeking the advice of legal counsel. Views expressed are those of the authors and not necessarily this law firm or its clients.