For the first time, a large group of companies doing business in California must publicly report their greenhouse gas emissions. Senate Bill 253 — the Climate Corporate Data Accountability Act — moves from statute to practice this year, with the first submittals due to the California Air Resources Board (CARB) on November 10, 2026.
CARB's guidance for this first cycle is notable for its tone. Rather than opening with penalties, it opens with pragmatism. For 2026, CARB will exercise enforcement discretion — a signal that the agency wants companies to start the habit of reporting well, not to be punished for imperfect first attempts.
What the first cycle actually requires
Reporting entities are expected to disclose Scope 1 and Scope 2 emissions for a prior fiscal year, drawn from information they already possess or were reasonably collecting as of December 5, 2024. Companies that were not yet gathering that data by then are not expected to submit Scope 1 and 2 figures for this first cycle, though CARB encourages them to file a statement of non-reporting rather than stay silent.
Limited assurance formally enters the picture in 2026, but here too CARB's enforcement discretion applies: submissions will be accepted without assurance for this first year. The direction of travel is clear even if the first step is gentle — assured, comparable emissions data is where this is heading.
“CARB is asking for a credible start, not a perfect finish. The companies that treat year one as foundation-building will be the ones ready when the discretion ends.”
The detail that separates a filing from a report
CARB encourages companies to add context — methodologies, boundaries, the emission-factor datasets used for Scope 2, and a candid account of what is and isn't captured yet. That is where a bare compliance filing becomes something a reader can actually trust and interpret. The choices you document now — organizational boundaries, data sources, Scope 2 factor options — become the baseline every future cycle is measured against.
- Confirm whether you meet the reporting-entity threshold and which fiscal year you'll report
- Assemble the Scope 1 and Scope 2 data you already hold, and document its sources and boundaries
- Decide and record your Scope 2 emission-factor approach so it's consistent year over year
- If you can't report yet, prepare a clear statement of non-reporting rather than going dark
- Treat assurance-readiness as a 2027 goal you begin building toward now
Why this is a communications question, not just a compliance one
SB 253 data will not live in isolation. It will be read alongside your annual report, your sustainability disclosures, and your investor materials — and it needs to tell the same story they do. The risk in year one is not the calculation; it is disconnection, where a new regulatory filing says something subtly different from everything else you publish.
At Big Pivot Partners, we see the first SB 253 cycle as an architecture moment. Get the boundaries, the data, and the narrative right once, and every future submittal — assured, disaggregated, and scrutinized — becomes an extension of a story you already tell clearly. The full CARB guidance is available below.
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