SB 253 Assurance Requirements: How to Prepare

California’s Climate Corporate Data Accountability Act (SB 253) is reshaping how organizations approach greenhouse gas (GHG) emissions reporting. With mandatory third-party assurance requirements for Scope 1, 2, and eventually Scope 3 emissions, companies must now ensure their data is not only accurate but also assurance-ready.

What is SB 253?

California’s Climate Corporate Data Accountability Act (SB 253) requires companies with over $1 billion in annual revenue doing business in the state to publicly disclose their GHG emissions. Starting in 2026, organizations must report Scope 1 and 2 emissions, followed by Scope 3 in 2027. These disclosures must be verified by an independent third party, introducing new technical and compliance challenges for ESG reporting teams.

Why SB 253 matters

SB 253 marks a major shift in climate accountability, requiring organizations to move from voluntary reporting to regulated, third-party assured disclosures. It raises the bar for data quality and transparency, impacting how companies collect, manage and calculate emissions data across their operations and supply chains.

What you’ll learn

This session is designed to help professionals across departments understand the technical requirements of SB 253 and prepare their organizations for third-party assurance. Our experts will share practical strategies, real-world examples and insights from working with customers across industries.

Key topics include:

• Understanding SB 253’s assurance mandate
• Navigating applicable assurance frameworks and standards
• Establishing internal controls and following best practices
• Our approach to assurance

Whether your organization is just beginning to develop an SB 253-compliant GHG statement or have already developed one and are preparing for third-party assurance, this session will provide actionable insights to maximize your readiness success.

The panel includes our seasoned assurance professionals with deep expertise in GHG disclosure for regulatory compliance. They will share real-world examples, answer audience questions, and offer guidance tailored to your industry and reporting maturity.

• Adrian Wain, Lead Verification Expert, UL Solutions
• Lauren Alexander, Lead Verification Expert, UL Solutions