This year's SB 253 reports are due November 10, 2026. Ahead of that deadline, the California Air Resources Board (CARB) has published new guidance for reporting entities and launched a voluntary intake platform for submissions.
Not much. As Ropes & Gray notes in its summary of the guidance, the new material is consistent with CARB's prior guidance and does not add new requirements. The two concrete additions are a voluntary intake platform and a reaffirmation of the enforcement discretion CARB first laid out in its December 5, 2024 Enforcement Notice.
Entities can submit Scope 1 and 2 data for their prior fiscal year based on whatever information they already had, or were already collecting, when the December 2024 notice went out. If your company wasn't collecting or planning to collect that data at that point, CARB does not expect you to submit Scope 1 and 2 data this year, but they do still expect you to respond.
CARB reiterated that reporting entities have options for this year's format. You can:
None of these is mandatory over the others. CARB is also encouraging entities to go beyond the bare numbers with context: methodologies, data sources, global warming potential values, emission factors, organizational boundaries, data broken out by category and gas, and any assumptions used. The draft template includes example questions for exactly this kind of detail.
Companies calculating Scope 2 emissions typically lean on the EPA's eGRID dataset and this year, the EPA hasn't released eGRID 2024 on its normal schedule. CARB's guidance addresses that gap directly: entities can use the most recent official release (eGRID 2023), the eGRID 2024 dataset published by the Cornerstone Sustainability Data Initiative (built from the EPA's own public source code), or another credible emission factor source. CARB isn't mandating one dataset but it is requesting companies to identify whichever factors and sources they use.
CARB's new platform is optional this year, and it does a few different jobs:
Worth flagging: uploaded emissions reports and statements of non-reporting submitted through the platform will be made public. CARB has also published a video tutorial for entities using it. Email submission to climatedisclosure@arb.ca.gov remains available for anyone who'd rather not use the platform.
CARB will issue 2026 invoices on or before December 10, with payment due 60 calendar days from the invoice date. Under its first-year enforcement discretion, CARB will accept submissions that haven't been assured.
CARB's second rulemaking, covering reporting requirements for 2027 and beyond, is already underway. At a July 2026 workshop, CARB previewed the assurance requirement currently proposed for 2027, which would apply to Scope 1 and Scope 2 emissions only — not Scope 3. Second, CARB has proposed narrowing mandatory Scope 3 reporting to five categories: purchased goods and services, fuel- and energy-related activities, waste generated in operations, business travel, and employee commuting. The remaining ten Scope 3 categories would be voluntary for now. Both points are still proposals moving through CARB's rulemaking process, not finalized requirements.
CARB has been clear that this year's flexibility — unassured submissions, choice of emission factor source, multiple reporting formats — comes from first-year enforcement discretion, not a permanent lowering of the bar. A separate rule-making already underway will address assurance and methodology for 2027 and beyond. Reporting entities that use this year's discretion to build real systems — clean Scope 1 and 2 data, documented methodology, defensible emission factor choices — will be better positioned once that rulemaking lands.
Do I have to use CARB's intake platform? No. It's voluntary this year. You can still submit by email to climatedisclosure@arb.ca.gov, or through any of the four reporting formats CARB outlined.
What if I wasn't collecting Scope 1 and 2 data as of December 2024? CARB doesn't expect you to submit that data this year. Submit a statement of non-reporting on company letterhead instead, either through the platform or by email.
Do I need third-party assurance for this year's report? No. CARB will accept unassured submissions for 2026 under its first-year enforcement discretion.
Is a specific Scope 2 emission factor dataset required? No. You can use eGRID 2023, the Cornerstone Sustainability Data Initiative's eGRID 2024, or another credible source (just identify which one you used).
When are fees due? CARB will send invoices on or before December 10, 2026, with payment due within 60 calendar days.
Note: SB 261's climate-related financial risk disclosure requirement is on a separate track and the injunction is still standing. It isn't addressed in CARB's latest SB 253 guidance. See our coverage above for where that stood as of last fall's CARB workshop.
John Davies is the Director of Content at thinkPARALLAX. With more than 15 years of experience in journalism, editorial leadership, and sustainability communications, he specializes in sustainability reporting, thought leadership, and brand storytelling.