California’s SB 253 — also known as the Climate Corporate Data Accountability Act — mandates one of the most comprehensive greenhouse gas (GHG) disclosure regimes in the world. If your company meets the $1B revenue threshold and operates in California, you’ll soon be required to report emissions across Scope 1, Scope 2, and Scope 3 — each representing different layers of your carbon footprint.

In this guide, we break down what each scope covers, what the law expects, how timelines differ, and what it takes to actually get your data ready.

Quick Overview: What Is SB 253?

SB 253 requires all companies with over $1 billion in annual revenue that do business in California to report full-scope emissions — Scope 1, 2, and 3 — starting as early as 2026.

The bill emphasizes standardized, verified data and mandates public disclosure via a central platform. It also requires third-party assurance for Scope 1 and 2 starting in 2026, with Scope 3 assurance to be phased in later.

Learn more: What is California’s SB 253?

What Are Scope 1, 2, and 3 Emissions?

Scope 3 is typically the largest chunk of emissions — and the hardest to measure.

What SB 253 Requires for Each Scope

Scope 1 and 2:

• Must be reported annually starting 2026
• Must be publicly disclosed through a state-contracted platform
• Must follow the GHG Protocol Corporate Standard
• Require limited assurance by an accredited third party
  

Scope 3:

• Reporting starts in 2027, 180 days after Scope 1 and 2 disclosures
• Must follow the GHG Protocol Corporate Value Chain Standard
• Third-party assurance isn’t required yet, but the law allows for future updates
  

Primary and secondary data sources — including proxy data — are allowed for Scope 3, but must be clearly documented.

Reporting Timelines You Need to Know

How to Prepare: Data Sources, GHG Protocol, and Tools

Start With These Steps:

1. Conduct a data inventory: List all assets and activities across business units that produce emissions.
   
2. Map emission sources to Scope 1, 2, or 3
   
3. Align with GHG Protocol:
   
   • Use the Corporate Standard for Scope 1 & 2
   • Use the Value Chain Standard for Scope 3
     
4. Choose the right calculation methods:
   
   • Direct measurement (e.g., fuel logs, meter data)
   • Emission factors (e.g., EPA, DEFRA databases)
   • Spend-based or hybrid models for Scope 3
     
5. Document methodologies: Transparency matters. CARB expects clear disclosure of assumptions and sources.
   
6. Prepare for assurance: Align your internal process with limited assurance frameworks (like ISAE 3000 or equivalent).
   

Common Pitfalls in Scope Reporting

• Incomplete Scope 3 value chain mapping
• Inconsistent emission factors across business units
• Overreliance on proxy data without explanation
• Misaligned fiscal year vs reporting year
• No audit trail for changes or data overrides
  

How Sprih Supports Scope 1, 2, and 3 Disclosures

Sprih’s platform was built with SB 253 in mind. Here’s how we help:

• Automated data collection across Scope 1, 2, and 3
• GHG Protocol-compliant calculators and emission factor libraries
• Integrated workflows to collaborate across teams and business units
• Audit-ready exports for third-party assurance
• Dynamic Scope 3 modeling for complex supply chains
• Support for multiple reporting frameworks (SB 253, CSRD, SEC)

You don’t have to build your emissions process from scratch — Sprih plugs into your current systems and evolves with your compliance needs.

Talk to our team or Download our SB 253 Checklist.