Governance & Policy
California SB 253 — Climate Corporate Data Accountability Act
Definition
California Senate Bill 253, the Climate Corporate Data Accountability Act, enacted in 2023 and amended by SB 219, requires US entities with over one billion dollars in revenue doing business in California to disclose Scope 1 and 2 emissions annually from 2026 and Scope 3 emissions from 2027, under rules administered by the California Air Resources Board, with limited assurance phasing in from 2027.
References
Scope, thresholds and reporting timeline
Underlying emissions accounting framework
Overview
What it means
Thousands of large companies face state-level emissions disclosure in the US even as the federal SEC climate rule is being rescinded, with first Scope 1 and 2 reports due in November 2026.
How it is used
Companies build CARB-compliant inventories and assurance-ready data trails; suppliers anticipate Scope 3 data requests from covered customers.
Why it matters
It is the most consequential US climate disclosure mandate currently in force, effectively setting a national baseline through California's market size.
Current status note
Scope 3 categories, assurance standards and future deadlines are still being refined in CARB rulemaking; verify current requirements before publication.