On October 12, 2026 the California Office of Administrative Law approved the California Air Resources Board’s Initial Regulation for SB 253 and SB 261. The regulation took effect the same day and fixed November 10, 2026 as the first reporting deadline for Scope 1 and Scope 2 greenhouse gas emissions under the Climate Corporate Data Accountability Act. Covered entities are U.S.-organized companies with more than $1 billion in annual revenue that do business in California. CARB’s preliminary list identified more than 4,000 such companies.
For the 2026 cycle companies may submit data they already possessed or were collecting as of December 5, 2024, or a statement of non-reporting if they were not collecting it. Limited assurance is not required this year. Scope 3 reporting is deferred to 2027. The companion SB 261 climate-related financial risk reports for companies above $500 million remain enjoined by the Ninth Circuit; enforcement is stayed. The Scope 1 and 2 obligation is not.
The number that matters for underwriting desks
November 10 is the date. Between now and then, a defined set of large companies must produce Scope 1 and Scope 2 inventories or affirm they do not have them. That data set does not yet include the full value-chain numbers that will arrive next year, but it is the first standardized U.S. state-level emissions file of this scale.
Carriers that already price physical climate risk, transition risk, and business-interruption exposures will see a new public or semi-public data source. Brokers who place property, builders risk, and professional lines for companies near the $1 billion threshold will be asked, before the end of the month, whether their clients are in scope and what the filing will contain.
What the 2026 reports will and will not show
Scope 1 is direct emissions from owned or controlled sources. Scope 2 is purchased energy. For a commercial real-estate owner or a large facilities operator those numbers are largely the utility and fuel bill. They are not the contractor Scope 3 Category 1 purchased-services numbers that will matter in 2027, nor are they the physical-risk scenario analyses that SB 261 would have required if the injunction is lifted.
Still, the existence of a dated, regulated filing changes the information asymmetry. An underwriter reviewing a property submission for a large corporate insured can now ask whether the Scope 1 and 2 inventory has been prepared, what base year was used, and whether the same methodology will feed later Scope 3 work. The Initial Regulation also imposes a five-year record-retention obligation for the California tax records that support the revenue-threshold determination. That is an audit trail that did not previously exist in standardized form.
Claims and endorsement implications that are already live
The immediate claims effect is limited. SB 253 does not rewrite policy forms or create a new coverage trigger. What it does create is a documentation expectation. When a large insured files a property or business-interruption claim in 2027 or later, the existence of a prior regulated emissions inventory may be referenced in questions about operational continuity, energy-dependency, or mitigation steps taken after the loss.
Builders-risk and professional-lines carriers that already see ESG language in owner-contractor agreements (the IFMA Pulse figure of 45 percent of facilities managers adding such provisions is the recent benchmark) will see those clauses justified by a concrete regulatory date. Price-escalation and data-security riders were already rising; emissions-data cooperation language now has a calendar behind it.
Broker actions before the deadline
Identify which clients sit above the $1 billion threshold and do business in California. Confirm whether they received CARB’s reminder letter. For those that will file, note the submission path (CARB’s voluntary platform or email) and the fact that 2026 data need not be assured. For those that will file a non-reporting statement, document the basis so it can be explained later if underwriters ask.
Fees under the Initial Regulation are calculated by dividing CARB’s program costs by the number of covered entities. Earlier staff estimates placed the SB 253 fee near $3,106. The determination notices are scheduled for December 10, with payment due within 60 days. The fee itself is not a coverage issue; the existence of a regulated reporting regime is.
SB 261 remains on hold. Until the Ninth Circuit lifts the injunction or the appeal is resolved, climate-related financial risk reports are not enforceable. The Scope 1 and 2 numbers that start arriving after November 10 are enforceable. Carriers and brokers that treat the emissions filing as the first regulated climate data point for large U.S. companies, rather than waiting for the financial-risk report, will be aligned with the rule that is actually live.
How the data will show up in property and builders-risk submissions
Large corporate insureds already submit energy-use and business-continuity information on property applications. After November 10, underwriters can ask for the same numbers that were filed with CARB. Consistency between the regulatory filing and the underwriting submission becomes a simple cross-check. Discrepancies will be visible without new modeling.
Builders-risk placements for projects owned by covered entities will see the same pressure. If the owner is preparing a Scope 1 and 2 inventory, temporary generators, fuel use during construction, and purchased electricity for the job site are already inside the organizational boundary. Contractors who can supply those figures without delay reduce friction on both the regulatory filing and the insurance application.
Professional-lines carriers writing management liability or D&O for companies near the threshold will note the existence of a dated compliance obligation. Failure to file, or a material error in the filing, creates a potential governance issue even if the financial-risk report under SB 261 remains stayed. The 2026 Scope 1 and 2 cycle is the first enforceable test.
The practical broker checklist is short. Confirm scope status this week. Document the filing path or the non-reporting basis. Note the December 10 fee-determination date so clients are not surprised. When Scope 3 arrives in 2027, the same clients will need contractor data; the underwriting conversation can start now with the numbers that are already due.
The OAL approval on October 12 did not create new physical risk. It created a regulated data point that carriers and brokers can now reference with a specific date and a specific revenue threshold. That is the hard number that moved this week.