California’s SB 253 — officially known as the Climate Corporate Data Accountability Act — is set to become one of the most significant climate disclosure regulations in the U.S. Use this SB 253 compliance checklist to prepare your company for California’s Climate Corporate Data Accountability Act, which mandates Scope 1, 2, and 3 GHG emissions disclosure starting in 2026.
If you’re a sustainability, compliance, or finance leader at a company with over $1 billion in global revenue, this blog is for you. We’ll walk you through everything you need to know to prepare for SB 253, including a step-by-step compliance checklist, key dates, assurance requirements, and links to additional guidance.
Senate Bill 253 is a California law passed in October 2023. It mandates that large companies disclose their full GHG emissions footprint every year. These disclosures must be:
The goal is to give regulators, investors, and consumers greater transparency into corporate emissions, especially Scope 3, which includes supply chain and product use emissions.
You’re considered a “reporting entity” under SB 253 if:
Note: Even private companies are covered if they meet the above criteria.
| Emission Type | First Reporting Year | Deadline |
| Scope 1 & 2 | 2026 | TBD by CARB (expected mid-2026) |
| Scope 3 | 2027 | 180 days after Scope 1 & 2 deadline |
CARB (California Air Resources Board) will finalize the exact reporting dates by January 1, 2025.
Each reporting entity must annually disclose:
Disclosures must be aligned with the Greenhouse Gas Protocol and clearly identify any assumptions, methodologies, or proxy data used.
Direct emissions from sources you own or control — e.g. fuel burned in company vehicles, onsite boilers.
Indirect emissions from energy your company buys — e.g. electricity, steam, cooling.
All other indirect emissions in your value chain. These are often the largest — and most difficult to track.
Common examples include:
SB 253 requires third-party assurance, with increasing rigor over time:
| Year | Scope 1 & 2 Assurance Level | Scope 3 Assurance Level |
| 2026 | Limited | None (Voluntary) |
| 2027 | Limited | Voluntary (review underway) |
| 2030 | Reasonable | Limited |
All assurance providers must:
Here’s what your internal teams need to start doing now.
Starting in 2027:
Note: Between 2027–2030, Scope 3 penalties apply only to non-filing, not errors.
Sprih works with climate and compliance teams across global companies to:
If you’re working on your SB 253 roadmap, we’ve created a detailed prep checklist + implementation toolkit. Want access? Drop us a note at hello@sprih.com.
SB 253 is not just another disclosure law — it’s a signal that climate data is now investor-grade data.
Start working through your SB 253 compliance checklist now—early preparation reduces reporting costs, avoids penalties, and positions your company as a climate accountability leader.
Need help making sense of it all? Reach out to Sprih — we’d be happy to share what’s worked for others in your shoes.