SB 253 reporting software: California climate disclosure for Scope 1, 2 and 3 emissions

Two things about that table are worth saying out loud, because they change what you should be doing this quarter. First, the threshold is tested on total revenue, not California revenue, using the lesser of your previous two fiscal years. A company with $1.2 billion in global revenue and one sales office in California is in scope. Second, "doing business in California" is a broad test, and plenty of companies that do not think of themselves as California companies meet it.

The deadline has moved once and could move again. CARB adopted its initial regulations on February 26, 2026 with an August 10, 2026 first-year deadline, then announced on June 24, 2026 that it intends to defer that date to November 10, 2026 through an expedited rulemaking. Treat November 10 as the working date, and check the CARB program page before you rely on it, because the rulemaking is still open.

On September 1, 2026 CARB published the material for the first cycle: reporting guidance, a voluntary online intake platform, an optional Scope 1 and Scope 2 template and an instructional video. Use of the platform is voluntary and entities may still submit by email, but it is where CARB collects fee contact details and entity identification, and it asks for a legal name as filed on tax forms, a Federal EIN or California Corporation Number or Secretary of State file number, and a California Principal Business Activity code for each in-scope subsidiary. Our walkthrough of what to file by November 10 and what the intake platform asks for covers the fields and the first-year discretion.

SB 253 applies to entities formed in the United States with more than $1 billion in total annual revenue that do business in California. Revenue is measured on the lesser of the entity's previous two fiscal years, so a single strong year does not pull you in, and a single weak year does not push you out. Parent companies report on a consolidated basis, and subsidiaries covered by a parent's report generally do not file separately.

The second half of that test is where most companies get the answer wrong, because the statute never defines what doing business in California means. CARB's regulation fills the gap by borrowing California's existing franchise-tax test: an entity is doing business in the state if it is organized or commercially domiciled there, or if its California sales exceed a set threshold, given as $735,019 for 2024 and $757,070 for 2025 because the Franchise Tax Board indexes it every year, and applied as the lesser of that figure or 25% of the entity's total sales. That is a low bar against a $1 billion revenue floor. A billion-dollar manufacturer headquartered in Ohio with under a million dollars of California sales is in scope, and consolidation follows the approach used in the Cap-and-Invest program.

There is also a fee, and it is separate from everything else on this page. CARB charges a flat annual fee to every covered entity, the same amount for each rather than one scaled to revenue, set by dividing total program cost across the reporting population. CARB's earlier estimates put it near $3,106 for an SB 253 reporter and $1,403 for an SB 261 reporter. CARB's modifications of July 27, 2026 moved the written fee determination to December 10, 2026, with payment due within 60 calendar days of that notice, so the fee no longer sits one day ahead of the emissions report as originally drafted. That package is modified proposed text rather than law: it still has to clear review at California's Office of Administrative Law, which had not happened as of late August 2026, so budget against the December date but confirm it before you commit a payment date. Parent entities may pay on a consolidated basis for their subsidiaries.

The first Scope 1 and Scope 2 report is due November 10, 2026, after CARB announced on June 24, 2026 that it would defer the original August 10, 2026 date by three months. Which fiscal year you report depends on your year end: entities whose fiscal year ends between January 1 and February 1, 2026 report fiscal 2026 data, and entities whose fiscal year ends after February 1 report fiscal 2025 data. The intent is to give every filer at least six months after year end.

If you also run an industrial site, note that a second federal deadline lands nine days earlier: EPA's Greenhouse Gas Reporting Program report for reporting year 2025 is due October 30, 2026. It is a different obligation with different prescribed methods and it does not satisfy SB 253, a distinction worked through in EPA GHG reporting vs SB 253.

Less than most companies expect, and CARB has been unusually explicit about it. For the 2026 cycle only, strict compliance with CARB's draft reporting template is not required and limited assurance is not required. The dated version of all of this, including CARB's July 27, 2026 modifications and the fee determination that moved to December 10, sits on California climate disclosure software. You report Scope 1 and Scope 2 in metric tons of carbon dioxide equivalent, together with the source data and assumptions behind the figures, and you may base them on information you already possessed or were already collecting as of the December 5, 2024 enforcement notice. CARB plans a voluntary online intake platform for fee contact information and emissions reporting, alongside a guidance document. The template becomes mandatory with 2027 filings.

There is a route for companies that genuinely have nothing. An entity that was not collecting emissions data, and had no plans to when the enforcement notice was issued, may submit a statement on company letterhead saying it did not file, giving its reason and its good-faith efforts. Treat that as a disclosure of its own rather than a loophole: it goes on the record, it does not carry into 2027, and documented good faith is a statutory mitigating factor rather than a defence. What CARB can fine you for is set out in SB 253 penalties.

CARB had to price its own rule before it could adopt it, and the resulting figures are the only published per-company benchmark this market has. They come from CARB's Standardized Regulatory Impact Assessment, presented at its March 2026 public workshop, and CARB invited comment on their accuracy.

The gap between the first two rows is the part worth noticing: adding all fifteen Scope 3 categories to an existing Scope 1 and 2 inventory costs an estimated $13,954 a year, not another full inventory, because the boundary, the factor policy and the classified ledger already exist. First-year costs run higher, between $167,102 and $191,391 depending on which Scope 3 phase-in CARB adopts for 2027. The full breakdown, including which of these lines you can actually move, is in SB 253 compliance cost, and the build-versus-buy question behind it is on carbon accounting services.

Yes, but not yet. Scope 3 disclosure begins in 2027, and CARB is still running pre-rulemaking on the Scope 3 framework, organizational boundaries, accounting methods and assurance standards. That gap is the whole planning opportunity. Scope 3 is where the data problem lives, it usually accounts for the large majority of a corporate footprint, and the companies that treat 2026 as a Scope 1 and 2 exercise will start 2027 from nothing. The 15 Scope 3 categories are the map, and Scope 3 reporting covers the method.

Not for the first submission. CARB has said it will exercise enforcement discretion and accept Scope 1 and Scope 2 data companies already hold or were already collecting, whether or not it received limited assurance. That relief is specific to the 2026 reporting cycle. Limited assurance over Scope 1 and Scope 2 begins with reports submitted in 2027, which is an argument for building an inventory that could survive assurance now rather than assembling one that cannot. The full ladder through 2030, and the five standards CARB accepts for an engagement, are set out in SB 253 assurance requirements. What CARB can actually fine you for, and the statutory $500,000 ceiling on it, are covered in SB 253 penalties.

SB 253 is a number, SB 261 is a narrative. SB 253 makes you publish a measured GHG inventory. SB 261 makes you publish how climate change threatens your business and what you are doing about it, at a lower $500 million revenue threshold, every two years. SB 261's January 1, 2026 statutory deadline is currently not being enforced: a Ninth Circuit injunction is in play and CARB has said it will set an alternate date once the appeal resolves. Most companies over $1 billion are in scope for both.

That is the shape of our carbon accounting software: it starts from the accounts payable and utility data you already have, classifies it to GHG Protocol scopes and categories, and keeps the line-level evidence attached so the number has a provenance instead of a vibe. You can run the classifier on your own lines in the demo above, before you talk to anyone. If your exposure is European rather than Californian, CSRD reporting software and CBAM reporting cover those regimes, and ESG reporting software is the wider category view. Comparing vendors is on best carbon accounting software.