On October 12, 2026, the California Office of Administrative Law approved the California Air Resources Board’s Initial Regulation for SB 253, and the regulation took effect the same day. That approval locked the date every covered company now has to work to: the first Scope 1 and Scope 2 emissions reports under the Climate Corporate Data Accountability Act are due to CARB on or before November 10, 2026.
This is not a proposed rule and it is not a distant phase-in. It is a live filing, roughly three weeks out, for U.S. companies with more than $1 billion in annual revenue that do business in California. What follows is the practitioner version: exactly who is covered, which fiscal year goes into the first report, the ways CARB will accept the filing, what assurance does and does not require this year, and the preparation steps that still fit in the time left.
The filing in one table
| Item | What the approved rule requires |
|---|---|
| Who files | U.S.-organized business entities with revenue over $1 billion that do business in California |
| First deadline | November 10, 2026 |
| Scopes in the 2026 report | Scope 1 and Scope 2 only — Scope 3 is not required this cycle |
| Data year | Prior fiscal year, selected under the February 1 rule below |
| How to file | CARB’s voluntary 2026 Report Intake Platform, or email to [email protected] |
| Assurance | Limited assurance is the statutory standard from 2026, but CARB accepts 2026 filings with or without it |
| Fee | Annual, formula-based; CARB issues fee determination notices by December 10, payment due within 60 days |
| Penalty ceiling | Up to $500,000 per reporting year for nonfiling, late filing, or other failure to comply |
| Records | Keep the California tax records behind your applicability determination for five years |
Who must file — and who is out
The regulation defines a “reporting entity” as a partnership, corporation, limited liability company, or other business entity formed under the laws of California, another U.S. state, the District of Columbia, or an act of Congress, with total annual revenues in excess of $1 billion, that does business in California.
Three details of that definition decide most borderline cases. First, revenue means gross receipts, as defined in California Revenue and Taxation Code section 25120(f)(2). Second, the revenue test uses the lesser of the entity’s two previous fiscal years — one exceptional year does not pull an entity in, and one soft year does not let it out. Third, the test is applied entity by entity, at the individual business entity level; revenue from intercompany transactions inside the same combined reporting group does not count toward the threshold.
“Doing business in California” is also a defined term, not a vibe. It means doing business under Revenue and Taxation Code section 23101(a) and meeting either the section 23101(b)(1) or the section 23101(b)(2) test. Wholesale electricity sales in interstate commerce do not count toward the (b)(2) sales test. CARB’s guidance is explicit that entities are responsible for determining their own applicability — there is no approval step where CARB confirms your status for you.
Five categories are outside the article entirely:
- Tax-exempt nonprofit or charitable organizations
- Business entities regulated by the California Department of Insurance, or in the business of insurance in any other state
- Federal, state, and local government entities, and companies majority-owned (over 50 percent) by government entities
- Entities whose only California activity is wholesale electricity transactions in interstate commerce
- Entities whose only California business is employee compensation or payroll expenses, including teleworking employees
One structural relief valve matters for groups: reports may be consolidated at the parent-company level. A covered subsidiary does not have to file separately if its parent files a consolidated report that includes it.
Which fiscal year goes in the first filing
The first report covers a prior fiscal year, and section 96076(c) of the regulation picks which one by a February 1 line:
- Fiscal year ends on or before February 1 in a calendar year → report the fiscal year ending in the current calendar year.
- Fiscal year ends after February 1 → report the fiscal year ending in the previous calendar year. The entity may instead choose its most recent preceding fiscal year, if that data is available.
Worked through the common cases: a calendar-year filer reports its 2025 fiscal year. A company whose fiscal year ends June 30 reports the year that ended June 30, 2025 — but may elect the year ended June 30, 2026 if the data is ready. A company whose fiscal year ends January 31 reports the year ended January 31, 2026, because that year ends in the current calendar year under the first branch of the rule.
Scope for this cycle is deliberately narrow. Scope 1 is direct greenhouse gas emissions from sources the entity owns or directly controls, regardless of location, including fuel combustion. Scope 2 is indirect emissions from purchased or acquired electricity, steam, heating, or cooling, regardless of location. Scope 3 — the value-chain inventory — is not part of the 2026 report; under the statute it begins in 2027. Emissions are measured and reported in conformance with the Greenhouse Gas Protocol’s standards and guidance.
The no-data door, stated precisely
For the November 10, 2026 report only, the regulation carries forward CARB’s December 5, 2024 Enforcement Notice. A covered entity has two options:
- (A) Submit Scope 1 and Scope 2 emissions from its prior fiscal year that can be determined from information it already possessed or was already collecting on or before December 5, 2024; or
- (B) Submit a statement of non-reporting on company letterhead stating that it is not submitting a report because it did not possess Scope 1 or Scope 2 information and was not collecting it on or before December 5, 2024.
CARB asks that the statement be submitted through the intake platform or by email before November 10, 2026. Read this door for exactly what it is: a one-cycle enforcement-discretion posture for the first report, not an exemption from SB 253. An entity that uses it is still a reporting entity, still owes the fee, and still needs a real inventory for the next cycle. Our earlier briefing walks through the three doors into the filing in more depth.
How to file in 2026
CARB built a 2026 Report Intake Platform, and its status surprises people: use of the platform is voluntary, not mandatory. Ahead of the deadline it can carry your contact information, your Scope 1 and 2 report through its submission fields, and the billing information CARB needs for fee invoicing. The alternative route is plain email — send the emissions report and contact information to [email protected].
The first-year formats are equally pragmatic. CARB’s September 1, 2026 reporting guidance accepts an existing annual report that includes Scope 1 and 2 emissions, existing Scope 1 and 2 data already reported to other programs or voluntary initiatives, or CARB’s Draft Scope 1 and 2 GHG Reporting Template — which is itself voluntary for 2026. For Scope 2, no single factor dataset is mandated this year: EPA eGRID 2023, the Cornerstone Sustainability Data Initiative’s eGRID 2024, or other credible sources may be used, provided the filing identifies the factors and sources behind the numbers.
CARB also encourages filers to include the context around the numbers — methodologies, data sources, global warming potential values, emission factors, organizational boundaries, disaggregation by category and gas, and assumptions. That context is encouraged rather than mandated in the first-year guidance, but it is the cheapest defensibility a filer can buy: it is the record that shows how each number was produced.
Assurance: the requirement versus the first-year enforcement
The statute sets a real assurance ladder. Health and Safety Code section 38532 requires independent third-party assurance of the disclosure: limited assurance for Scope 1 and 2 beginning in 2026, rising to reasonable assurance beginning in 2030.
The first-year enforcement posture is different from the requirement, and conflating the two is the most common error in coverage of this filing. CARB’s FAQ and its September 2026 guidance state that CARB will accept 2026 submissions whether or not assurance has been obtained. The obligation did not move; the enforcement did. Assurance requirements for 2027 and beyond are part of CARB’s second rulemaking and are not settled by the Initial Regulation — so the correct 2026 posture is to file on time, and to build the inventory so that it can survive limited assurance when the second rulemaking lands.
Fees, penalties, and the five-year file
The fee is an annual implementation fee assessed per reporting entity, calculated by formula: CARB’s program costs are recovered across the number of covered entities, with contingency and debt components in the calculation. The approved regulation sets the mechanics, not a fixed dollar figure — anyone quoting you an exact per-company fee for 2026 is quoting an estimate, not the rule. CARB issues fee determination notices by December 10, and payment is due within 60 calendar days of the notice. A parent may pay on a consolidated basis, but the fee is still assessed per covered entity.
The penalty exposure sits in the statute. CARB’s penalty regulations may reach nonfiling, late filing, or other failure to meet the law’s requirements, and penalties imposed on a reporting entity shall not exceed $500,000 in a reporting year. In setting a penalty, CARB considers all relevant circumstances, including the entity’s past and present compliance and whether it took good-faith measures to comply, and when. Keep that separate from fee enforcement: under the fee subarticle, each calendar day of a violation is a separate offense, violations may be enjoined, and an unpaid fee is a separate violation for each day it remains unpaid. The $500,000 cap and the daily fee offenses are two different mechanisms, and a compliance calendar should track both.
Finally, the recordkeeping rule that outlives the deadline: entities must keep the California tax records that prove the revenue and doing-business thresholds for five years, and produce them on request. Your applicability memo is not a one-time work product; it is a five-year file.
What changed on the way to November 10
Companies that planned against the original calendar have already been whipsawed once, and the history explains the current date. SB 219 (2024) amended SB 253 and its companion law — among other changes it moved CARB’s deadline to adopt the implementing regulation and formalized parent-level consolidation. The Initial Regulation CARB approved on February 26, 2026 set the first filing deadline at August 10, 2026. CARB withdrew that package from the Office of Administrative Law on June 24, released modified text for a 15-day comment period on July 27 deferring the deadline to November 10, 2026, resubmitted the final package on September 21, and OAL approved it effective October 12, 2026.
The lesson is not that dates move. It is that this date has finished moving: the regulation is approved and in effect, and November 10 is the deadline in the operative text.
Preparation checklist: the next three weeks
- Close the applicability question in writing. Entity-by-entity revenue test on the lesser of the last two fiscal years, doing-business analysis, exemption check — signed off and filed for the five-year record.
- Pick the fiscal year deliberately. Apply the February 1 rule, and where the election exists, decide whether the most recent preceding fiscal year is genuinely ready or merely newer.
- Inventory what existed on December 5, 2024. That date decides whether you file numbers, file numbers built from what you had, or file the letterhead statement. Do not reconstruct this answer from memory in November.
- Choose the route and format. Intake platform or email; existing report, other-program data, or CARB’s draft template. Any of them beats a late bespoke build.
- Assemble the methodology context now. Boundaries, factors and their sources, GWP values, assumptions — while the people who produced the numbers still remember how.
- Set the assurance posture explicitly. Filing without assurance is accepted in 2026; arriving at the second rulemaking with an unassurable inventory is the real risk. Build to the limited-assurance standard even if no provider signs this cycle.
- Calendar December 10. The fee determination notice starts a 60-day payment clock, and it lands in the middle of year-end close.
- Read the filing the way your insurer will. A CARB submission is a dated, signed representation about your operations. Our sister desk at Risk Coverage Hub reads the same filing as a liability document — what a missed or inconsistent filing does to penalties, D&O applications, and renewals.
One tooling note for teams starting from zero: BC ESG’s Corporate Carbon Footprint Calculator can size a Scope 1, 2, and 3 footprint quickly enough to sanity-check an inventory in progress. Use it for exactly what it is — a planning estimate built on published U.S. EPA factors, in the page’s own words not an audit, not a GHG Protocol inventory, and not a certification. It is a reasonableness check on the filing, never a substitute for it.
Frequently asked questions
Is the November 10, 2026 deadline real, or is the regulation still proposed?
It is real. The Office of Administrative Law approved CARB’s Initial Regulation on October 12, 2026 and it took effect that day. The operative regulation sets the first Scope 1 and Scope 2 reports due on or before November 10, 2026. Older CARB web pages still carry some “proposed” language; the October approval and CARB’s September 1, 2026 reporting guidance control.
Our revenue crossed $1 billion once, two years ago. Are we covered?
Probably not on that fact alone — and the reverse is also true. Applicability uses the lesser of your two previous fiscal years’ gross receipts, measured entity by entity. One spike year above $1 billion with the other year below it leaves the lesser year under the line. Two years above it puts you in, even if the current year is softer.
We have no emissions data at all. What do we file?
For the 2026 report only, if you did not possess Scope 1 or Scope 2 information and were not collecting it on or before December 5, 2024, you may submit a statement of non-reporting on company letterhead, through the intake platform or by email, before November 10, 2026. That is a first-cycle enforcement posture, not an exemption — and the statement must be true. If you were collecting data for any purpose by that date, the honest route is to report what that data supports.
Do we have to use CARB’s intake platform?
No. The 2026 Report Intake Platform is voluntary. You may file through it — it also collects contact and billing information for fee invoicing — or email your emissions report and contact information to [email protected]. CARB’s own draft reporting template is likewise voluntary for 2026; an existing annual report or data already reported to another program can serve as the filing.
Is third-party assurance required for the 2026 filing?
The statute requires limited assurance of Scope 1 and 2 disclosures beginning in 2026, with reasonable assurance from 2030. For this first cycle, however, CARB has stated it will accept 2026 submissions whether or not assurance has been obtained. Treat that as enforcement discretion for one year, not a repeal: assurance requirements from 2027 sit in CARB’s second rulemaking.
What does the filing cost, and what does a miss cost?
The annual fee is formula-based — CARB’s program costs divided across covered entities — with determination notices issued by December 10 and payment due within 60 days; the regulation does not set a fixed dollar amount. A miss costs more: administrative penalties for nonfiling, late filing, or other failure to comply can reach $500,000 in a reporting year, with good-faith compliance efforts counted in the entity’s favor, and fee violations accrue as separate daily offenses on top of that.
Is SB 261 the same deadline?
No. SB 261 is the companion climate-risk reporting law for companies over $500 million, on a biennial cycle — and its enforcement is currently enjoined by the Ninth Circuit. November 10, 2026 is an SB 253 date, for Scope 1 and Scope 2 emissions, for companies over $1 billion. The two laws share a regulation but not a deadline, a threshold, or a current enforcement posture.