Which California companies must report emissions under SB 253 this year
California's Climate Corporate Data Accountability Act requires its first emissions disclosures this year, but CARB has already pushed the deadline back three months.
California's Climate Corporate Data Accountability Act, better known as SB 253, reaches its first live reporting cycle this year. The law tells large companies doing business in the state to publicly disclose their greenhouse gas emissions, starting with the categories known as Scope 1 and Scope 2.
The California Air Resources Board, which administers the law, has spent 2026 revising the rules companies must follow. It pushed back the first deadline, released new guidance and opened a voluntary online platform for submissions, all while a companion climate-risk law sits frozen by a federal appeals court.
Who has to report, and what counts as 'doing business here'
SB 253 applies to U.S.-organized entities with more than $1 billion in total annual revenue that also do business in California. CARB's regulation ties that revenue figure to the state's existing "gross receipts" definition in the Revenue and Taxation Code, and applicability is based on whichever of a company's two most recent fiscal years had lower revenue.
"Doing business in California" is defined narrowly for this purpose. An entity qualifies if it is organized or commercially domiciled in California, or if its California sales exceed a threshold that stood at $735,019 for the 2024 tax year, according to law firm summaries of CARB's rule. Companies confirm where they land using the same schedules they already file with the California Franchise Tax Board.
A separate, related law, SB 261, covers companies with more than $500 million in revenue and requires biennial disclosure of climate-related financial risk rather than emissions data. Enforcement of that law has been paused since a Ninth Circuit Court of Appeals injunction issued in November 2025, while SB 253 has continued moving toward its reporting deadline.
The deadline that moved twice
CARB's Initial Regulation, adopted in February 2026, originally set August 10, 2026, as the date companies had to submit their first Scope 1 and Scope 2 emissions reports. In June 2026, CARB announced it intended to defer that date by three months, to November 10, 2026, to give companies more time to prepare their first disclosures while the agency finished implementation details.
CARB carried out that change through an expedited rulemaking process. It withdrew the regulation it had submitted to the state's Office of Administrative Law in May 2026, published modified text on July 27, 2026, and ran a shortened 15-day public comment period that closed August 11, 2026. The result is a first-year deadline of November 10, 2026, for Scope 1 and Scope 2 emissions. Scope 3 emissions, which cover a company's supply chain and other indirect sources, are not due until 2027.
CARB has also proposed making November 10 the standing annual deadline going forward.
What companies actually have to submit this year
CARB has built flexibility into the first reporting cycle rather than requiring a single rigid format. On September 1, 2026, CARB staff published a guidance document for 2026 submittals along with an instructional video, spelling out how companies can comply using data they already have.
Companies may submit an existing annual report that already includes Scope 1 and Scope 2 emissions, emissions data they previously reported to another program or voluntary initiative, or CARB's own draft Scope 1 and Scope 2 reporting template. Companies that had not yet started collecting this data as of December 5, 2024, when CARB issued its enforcement notice for the law, can instead file a statement of non-reporting on company letterhead explaining why.
CARB has said that strict compliance with its draft template is not required for the 2026 cycle, and that limited third-party assurance of the numbers, something that becomes mandatory in later years, is not required this time either. The agency has indicated it will exercise enforcement discretion for companies that make good-faith efforts, even if their first-year reports are incomplete. Whatever companies submit, including non-reporting statements, will be made public.
“CARB has said that strict compliance with its draft template is not required for the 2026 cycle.”
A new platform, and a fee attached to every filing
Alongside its September guidance, CARB opened a Voluntary Reporting Intake Platform. Its use is optional: companies can instead email their submissions to CARB's climate disclosure address. The platform lets reporting entities supply contact and billing information ahead of the deadline and, for those who choose, submit their Scope 1 and Scope 2 data directly through the system.
That contact information matters because reporting under SB 253 comes with a bill. CARB has proposed an annual fee for each reporting entity, estimated at $3,106 for SB 253 filers, calculated by dividing the agency's estimated program administration costs across the expected number of in-scope companies. A parallel fee estimated at $1,403 applies to SB 261 filers. CARB set September 10, 2026, as the date to begin assessing these fees, funding two dedicated accounts: the Climate Accountability and Emissions Disclosure Fund and the Climate-Related Financial Risk Disclosure Fund.
What is still unsettled
SB 253's legal footing is not fully resolved. The U.S. Chamber of Commerce and other business groups sued CARB, arguing the disclosure mandates compel speech in violation of the First Amendment. A federal district court in Los Angeles declined to block the laws in August 2025, finding the challengers were unlikely to succeed on that claim. The Ninth Circuit heard oral arguments in the appeal, Chamber of Commerce v. CARB, on January 9, 2026, but had not issued a ruling as of this month. Its earlier injunction froze enforcement of SB 261 but left SB 253's reporting timeline in place.
The rules for 2027 and beyond are also still being written. CARB has previewed a framework that would align reporting methodology with the GHG Protocol, require limited third-party assurance using standards such as ISO or AICPA frameworks, and narrow Scope 3 reporting to five specific categories: purchased goods and services, fuel- and energy-related activities, waste, business travel and employee commuting. Those proposals have not gone through the full rulemaking process and remain subject to change.
Penalties for noncompliance are capped by statute at $500,000 per reporting year for SB 253, though CARB has signaled it intends to waive penalties this year for companies making documented good-faith efforts.
