On September 1, 2026, the California Air Resources Board (CARB) issued guidance and launched a voluntary reporting platform to help companies navigate the submission process for their Scope 1 and 2 greenhouse gas (GHG) emissions data under SB 253. Among other details, the guidance outlines and reiterates methods for submitting data, acceptable reporting formats, and CARB's approach to enforcement discretion for the initial reporting cycle.
Senate Bill (SB) 253 requires U.S. companies with total annual revenues greater than $1 billion that do business in California to disclose their Scope 1, 2, and 3 emissions and obtain independent third-party assurance of their data. Implementation is phased in, and 2026 reporting covers Scope 1 and 2 data for the prior fiscal year. Scope 3 disclosure, as well as assurance requirements for Scope 1 and 2 data, begin next year.
SB 253 Scope 1 and 2 GHG emissions reports are due November 10, 2026, following a three-month extension from the original August 10, 2026, deadline. CARB announced the extension in June as part of limited proposed changes intended to clarify the initial regulation governing 2026 reporting. These proposed revisions were made available for a 15-day comment period that ended on August 11, 2026.
SB 253 Submission Process: Voluntary Platform or Email
In conjunction with its reporting submission guidance, CARB launched a Voluntary Reporting Intake Platform for 2026 SB 253 reporting. Use of the platform is not mandatory, but companies subject to SB 253 requirements can leverage the tool for streamlining the data submission process.
Through the platform, companies can provide their contact information ahead of the November 10 reporting deadline to facilitate fee invoicing. Companies can also use the platform to submit their Scope 1 and 2 data or their statement of non-reporting in accordance with CARB’s notice of enforcement discretion (described below). Alternatively, companies may email their contact information and emissions reports or statement of non-reporting to [email protected].
Annual fees will begin in 2026. CARB will notify companies of the amount owed by December 10, 2026, and payment will be due within 60 calendar days. Companies should build fee planning and payment logistics into their reporting preparations.
Accepted Reporting Formats and Details
Acceptable formats for 2026 submissions include, but are not limited to:
- Existing annual report including Scope 1 and 2 GHG emissions.
- Existing Scope 1 and 2 data reported to other programs/voluntary initiatives.
- CARB’s Draft Scope 1 and 2 Template for reporting, released in October 2025.
CARB encourages companies to provide additional details and context for data if available. This may include methodologies, data sources, global warming potential values, emission factors, organizational boundaries, disaggregated emission data by category and gas, and any assumptions used.
As CARB has previously communicated, the prior fiscal year for 2026 Scope 1 and 2 reporting submissions are determined as follows:
- If a company’s fiscal year ends between January 1, 2026, and February 1, 2026, it should report data from the fiscal year ending in calendar year 2026.
- If a company’s fiscal year ends between February 2, 2026, and December 31, 2026, it should report data from the fiscal year ending in calendar year 2025. If available, a company may report more recent data.
CARB Enforcement Discretion
As previously announced in its December 5, 2024, Enforcement Notice, CARB is exercising enforcement discretion during the initial reporting period and will not take enforcement action against companies with incomplete reporting, provided they are acting in good faith. If a company was not collecting or planning to collect Scope 1 and 2 emissions data when the notice was issued on December 5, 2024, it is not required to submit GHG data in 2026. However, CARB requests that companies relying on this enforcement discretion submit a statement of non-reporting on their company letterhead before November 10.
Separate from CARB’s enforcement discretion, certain types of companies are exempt from SB 253 reporting, such as tax-exempt nonprofits.
Legal Status and 2027 Reporting Preparation
California’s climate reporting rules have been challenged in federal court, and as always we recommend companies continue to consult with their legal counsel on how to proceed. In November 2025, the U.S. Court of Appeals for the Ninth Circuit issued an injunction staying enforcement of SB 261, which requires climate risk reporting, pending resolution of an appeal. The injunction does not extend to SB 253 compliance.
CARB is currently developing the regulations that will govern the 2027 SB 253 reporting cycle, which is expected to include Scope 3 data and limited assurance over Scope 1 and 2 data. Given the complexity of GHG emissions reporting and the assurance process, especially during early years, companies may wish to begin preparing now to avoid a last-minute scramble to establish compliance.
Contact BDO for help navigating California climate reporting and other global compliance requirements.