California's Climate Reporting (SB 253) Deadline Is November 10. Haven't Started? You're Not Alone.

If your company does business in California and you just realized you may owe the state a greenhouse gas emissions report by November 10, 2026, take a breath. You are far from the only one. There is still time to respond well, and you do not need to become an environmental expert overnight; that is our job.

What happened: On October 12, 2026, California's Office of Administrative Law gave final approval to the rules for the state's new corporate climate disclosure law, Senate Bill (SB) 253. The rules took effect immediately. The first emissions reports are due to the California Air Resources Board (CARB) by November 10, 2026, already three months later than originally planned. CARB has opened an online portal for submissions and released guidance for this first reporting year.A related law, SB 261, which covers climate-related financial risk, is currently paused by a federal appeals court. That pause does not apply to SB 253.

Does this apply to me? If your company is a U.S. business with more than $1 billion in annual revenue that does business in California (a few exemptions apply, including certain nonprofits, insurers, and government entities), or if you are headquartered outside of the US, have more than $1 billion in annual revenue, and do business in California (e.g., Headquarters is in Canada, but have an office or manufacturing facility in San Diego, CA), this ruling applies to you.

You are expected to report the greenhouse gases from your own operations, including the fuel you burn, and from the electricity you buy. These are known as Scope 1 and Scope 2 emissions.

Who is directly affected? Commercial property owners, REITs, and property managers. Emissions sit in boilers, emergency generators, refrigerants, and the electricity buildings use. Owners below the revenue threshold are likely to hear from large tenants asking for building-level energy and emissions data.

Who is indirectly affected? Suppliers, subcontractors, and landlords of the larger businesses. This is the part we see that is missed. Soon, emissions information may be required to do business with these large commercial property owners, REITs, and property managers. If a customer, a tenant, an owner, or a general contractor has sent you a sustainability questionnaire, or asked for your "carbon footprint," "Scope 1 and 2 emissions," or "GHG data," this is likely why.

You may not owe the state anything, but you may owe your best customer an answer.

Why a template likely won't fit your business: Most emissions tools assume a tidy business: an office, a few buildings, and some company cars. That is rarely who calls us. We have clients in machine medical implants, finish aerospace parts, die cast metal, cure composites, fabricate stone, print metal parts, run laboratories, repair heavy equipment, and own and operate commercial buildings. Their emissions hide in places a generic tool will not ask about: furnaces and ovens, process gases and coatings, refrigerants, central plants, backup generators, forklifts, and fleets of mobile equipment.

Two shops that look alike on paper can run completely differently on the floor.

A note for general contractors: If you are a local general contractor or subcontractor with your own concrete batch plant, loaders, excavators, and trucks, most of your footprint is the fuel those machines burn and the materials in your mix. You have probably never tracked any of it as "emissions," and that is normal. The good news is that much of what is needed already lives in records you keep for other reasons; it just has not been looked at this way before.

A note for property owners. Utility bills, generator run logs, and refrigerant service records are the starting point for most buildings. Where tenants pay their own utilities, the work is sorting out which emissions belong to you and which belong to them, and that split is exactly where a generic tool tends to get it wrong.

How we work: One client at a time: We start by learning how your business actually runs, then shape the reporting around it rather than forcing your business into a form. We do our best work where things get nuanced: the unusual process, the shared facility, the equipment nobody else has. We translate the jargon, work alongside your team, and leave you with something you understand, and can stand behind.

FAQ:

When is the California climate reporting deadline? November 10, 2026, for the first Scope 1 and Scope 2 greenhouse gas emissions reports under SB 253.

We haven't started. Is it too late? No. This first year comes with real flexibility. Companies may report data from their previous fiscal year. Companies that were not collecting emissions data as of December 5, 2024 may submit a statement on company letterhead saying so, in place of a full report. No third-party verification is required this year, and CARB has said it will not penalize good-faith first-year submissions. That flexibility is temporary and still asks something of you, so the worst move is waiting.

What can wait? Supply chain (Scope 3) emissions reporting does not begin until 2027, and CARB's annual fee notices start going out December 10, 2026. For now, the focus is your own operations and the energy you buy.

We're a small company. Why is a customer asking for our emissions? Because their own reporting will depend on it. Answering well can protect the relationship and sometimes help win the next bid.

Do we need to buy special software? Not necessarily. The right approach depends on how your operation runs, which is why we start there.

Not sure where you stand? If you are reading not knowing where to start, please reach out. One short conversation will tell you what applies, what is realistic before November 10, and what can wait.

Sources:

• California Locks in November Deadline for First Corporate Climate Reports, ESG Today (Mark Segal), October 15, 2026
  https://www.esgtoday.com/california-finalizes-corporate-climate-reporting-rules-locking-in-november-2026-deadline/
• California’s Climate Disclosure Regulations Receive Final Approval Ahead of November Reporting Deadline, Morgan Lewis, October 13, 2026
  https://www.morganlewis.com/pubs/2026/10/californias-climate-disclosure-regulations-receive-final-approval-ahead-of-november-reporting-deadline
• Office of Administrative Law Approves CARB’s Initial Regulation Implementing SB 253, Hogan Lovells, October 2026
  https://www.hlc.com/en/publications/breaking-office-of-administrative-law-approves-carbs-initial-regulation