California SB 253 (Carbon Reporting)

California's Climate Corporate Data Accountability Act (SB 253) represents a seismic shift in US environmental regulation. Since the beginning of 2026, companies with over $1 billion in global revenue that "do business" in California—a deliberately broad definition—are required to publicly disclose their Scope 1 and Scope 2 greenhouse gas emissions. Moving into 2027, this expands to include the notoriously difficult Scope 3 (value chain) emissions. The data cannot be an estimate; it requires independent, third-party assurance, with penalties reaching $500,000 for non-filing or severe inaccuracies.

The ripple effect of SB 253 impacts companies of all sizes. Even if your company is well under the $1B threshold, if you supply a major retailer, tech giant, or manufacturer that operates in California, they must calculate *your* emissions to satisfy their Scope 3 obligations. Consequently, thousands of SMEs are now receiving urgent data requests from enterprise partners demanding verified carbon footprint data aligned with the GHG Protocol.

Sustalium provides the verifiable data architecture required for SB 253. For reporting enterprises, it serves as the central ledger to aggregate facility energy data, fleet usage, and supplier responses, directly linking raw data to the final carbon calculation for the assurance auditors. For suppliers, Sustalium allows you to calculate your product or corporate footprint once, attach your evidence, and securely share a standardized compliance pack with every California-bound client that requests it.