A high-level readiness brief for California’s Climate Corporate Data Accountability Act
by Lucas Willey & Meir Hasbani
California’s SB 253 introduces a new emissions reporting framework for companies with more than $1 billion in annual revenue. By August 10th of this year, organizations are encouraged to publicly disclose whatever Scope 1 and Scope 2 emissions data they have collected. Organizations are not required to fully report emissions data, with assurance, until 2027.
Scope 3 disclosures must also be reported by 2027, although assurance is not required until 2030. While many companies already track emissions internally, SB 253 shifts the expectations toward consistency, auditability, and year-over-year defensibility—closer to financial reporting than traditional sustainability communication.
Accurate and efficient SB 253 compliance programs share several common traits: clear governance, defined methodologies, reliable data systems, and structured processes for supplier engagement. These elements ensure organizations meet regulatory expectations efficiently. They reduce the risk of rework, last-minute remediation, or elevated assurance fees which increase costs.
Despite the delays in reporting, we think now is a good time for companies to begin developing their compliance programs. Below is a high-level view of what robust SB 253 readiness typically includes.
What SB 253 Readiness Entails
(A concise benchmark to help organizations gauge their preparedness.)
1. Governance & Ownership
A defined structure for who manages emissions reporting, who approves key decisions, and how cross-functional teams interact. Clear ownership helps organizations respond to regulatory changes and maintain consistency across reporting years.
2. Methodologies & Documentation
A stable, documented approach for calculating Scope 1, 2, and 3 emissions, aligned with the GHG Protocol and suitable for third-party assurance. Strong programs maintain clear rationales for boundaries, assumptions, and emission factors.
3. Data Architecture
Reliable data flows that support traceability and audit trails. This includes identifying where emissions data originates, how it is stored, and how it is reviewed. Effective systems make annual reporting predictable and reduce the burden on internal teams.
4. Supplier Engagement for Scope 3
A scalable approach for obtaining upstream and downstream information. This often includes templates, guidance, and a communication plan for suppliers, balanced with appropriate use of secondary data.
5. Controls & Assurance Preparation
Processes that provide confidence in data accuracy and completeness. Organizations that prepare early typically see smoother assurance cycles and lower external verification costs.
6. Reporting & Disclosure
A repeatable workflow for compiling and reviewing disclosures, aligned with CARB guidance. This includes internal review steps and a plan for how SB 253 reporting interacts with other regulatory frameworks.
Why Good Systems Matter
Organizations that establish these foundations early generally benefit from:
- Lower annual cost of compliance through reduced rework and fewer last-minute fixes.
- More stable assurance fees due to cleaner data and clearer documentation.
- Less operational disruption, since reporting becomes routine rather than reactive.
- Better alignment with emerging requirements from the SEC, EU, and other jurisdictions.
Effective SB 253 preparation is ultimately about efficiency and long-term durability. Organizations that build strong systems now will spend less time, effort, and money later.