For many multinational companies, California’s climate disclosure laws are becoming one of the most consequential reporting developments outside Europe. Under the Climate Corporate Data Accountability Act, known as SB 253, companies doing business in California with more than US$1 billion in annual revenue will be required to disclose greenhouse-gas emissions across Scope 1, Scope 2 and, later, Scope 3.
On 24 June 2026, the California Air Resources Board (CARB) announced it was updating its regulatory proposal to defer the first Scope 1 and Scope 2 reporting deadline from 10 August 2026 to 10 November 2026. CARB said the proposed delay would give reporting entities more clarity following final adoption of the implementing regulation, while allowing limited regulatory changes to be consulted on.
The important word is proposed. The revised deadline needs to pass through the updated rulemaking process, including a 15-day public comment period and approval by California’s Office of Administrative Law. But the direction is clear: companies should work toward a November deadline while closely tracking the final regulation.
For BSustainable Today readers, the delay should not be mistaken for a relaxation of expectations. It is better understood as a practical reminder of what modern sustainability reporting requires: reliable emissions inventories, clear organisational boundaries, GHG Protocol-aligned calculations, evidence trails and third-party assurance readiness.
SB 253 applies to both public and private businesses. That matters because many groups accustomed to investor-led disclosure regimes may not have previously faced mandatory emissions reporting in a major US state. The first report covers Scope 1 and Scope 2 emissions, while Scope 3 disclosure is scheduled to follow from 2027. Limited assurance is also built into the framework, increasing the need for robust controls from the start.
The delay gives in-scope companies a short period to address four priorities.
Confirm scope and ownership: determine whether the group meets the revenue and California “doing business” thresholds, then assign executive and board-level responsibility.
Lock the emissions inventory: reconcile legal-entity structures, operational-control boundaries, energy data and methodology choices before assurance work begins.
Treat assurance as a design requirement: retain evidence for activity data, emission factors, calculation changes and controls; do not attempt to bolt assurance on at the end.
Build for Scope 3 now: although Scope 3 reporting comes later, supplier-data gaps and estimation methods take time to address. The first reporting cycle should establish the data architecture needed for the next one.
There is also a broader lesson for global reporters. California SB 253 will sit alongside CSRD, ESRS, UK SRS, ISSB-based regimes and other local requirements. The efficient response is not to build a separate reporting process for each rule, but to create a common emissions-data foundation that can support multiple disclosures, with jurisdiction-specific overlays where needed.
The November extension is welcome, particularly while CARB completes its rulemaking. But it is not spare time. It is the final preparation window for companies to turn GHG data into controlled, assured and decision-useful reporting.
Source: CARB’s 24 June 2026 bulletin and legal analyses of the proposed SB 253 deadline change and implementation process.