What is the timeline for SB 253 and SB 261 compliance?

The SB 253 and SB 261 compliance timeline begins with 2026 reporting obligations. SB 253 requires annual Scope 1 and Scope 2 emissions disclosures starting in 2026, followed by Scope 3 reporting in 2027. SB 261 requires the first climate-related financial risk report by January 1, 2026, and then every two years thereafter.

When does SB 253 reporting start?

SB 253 reporting starts in 2026 using fiscal year 2025 data for Scope 1 and Scope 2 emissions. Scope 3 emissions reporting begins in 2027, typically within 180 days after the Scope 1 and Scope 2 disclosures.

When is the first SB 261 report due?

The first SB 261 climate-related financial risk report is due by January 1, 2026. After that, companies must publish an updated report every two years, such as in 2028, 2030, and so on.

What happens in 2030 under the SB 253 timeline?

In 2030, SB 253 moves to stricter assurance requirements. Scope 1 and Scope 2 emissions disclosures must obtain reasonable assurance, and Scope 3 disclosures move into limited assurance requirements.

Do companies need to prepare before 2026?

Yes, companies should begin preparation well before 2026 by building greenhouse gas inventories, establishing governance controls, collecting supplier data for Scope 3, and aligning climate-risk reporting workflows with TCFD or IFRS S2 standards.

How often must companies report under SB 253 and SB 261?

SB 253 requires annual emissions reporting every year once reporting begins, while SB 261 requires biennial climate-risk reporting every two years.

Why is understanding the SB 253 and SB 261 timeline important?

Understanding the timeline helps companies allocate resources, engage assurance providers early, avoid compliance penalties, and build systems that can support long-term climate reporting requirements across multiple jurisdictions.

Timeline for California Climate Disclosures: SB 253 & SB 261

2 min. read
Anviksha Mishra

Businesses must understand the SB 253 and SB 261 timeline as California’s climate compliance clock ticks, with mandatory emissions and risk reporting starting in 2026.

This timeline breaks down the major deadlines, what’s required, and how to prepare.

At-a-Glance: Key Dates

Date	Requirement
Jan 1, 2025	SB 253 regulations must be adopted
Jan 1, 2026	First SB 253 Scope 1 & 2 disclosures due
Jan 1, 2026	First SB 261 risk report due
2027 (mid-year)	SB 253 Scope 3 disclosures begin (180 days after Scope 1 & 2)
2030	Reasonable assurance required for Scope 1, 2, and Scope 3 emissions

Visual Timeline

SB 253 and SB 261 timeline reporting requirements demand companies with $1B+ in annual revenue doing business in California disclose emissions annually.

SB 253: Emissions Disclosure Timeline

Applies to: Companies with $1B+ in annual revenue doing business in California
What’s required: Annual public disclosure of Scope 1, 2, and 3 GHG emissions
Standard: Greenhouse Gas Protocol
Assurance: Third-party limited (then reasonable) assurance required

Timeline:

Year	Disclosure	Notes
2025	CARB adopts implementing rules	Deadline: Jan 1, 2025
2026	First Scope 1 & 2 reporting	Must follow GHG Protocol
2027	First Scope 3 reporting	Due within 180 days after Scope 1 & 2
2030	Reasonable assurance begins	For Scope 1, 2, and 3 (if required)

SB 261: Climate Risk Disclosure Timeline

Applies to: Companies with $500M+ in revenue doing business in California
What’s required: Biennial climate-related financial risk reports
Standard: TCFD (or equivalent, e.g. ISSB)
Disclosure: Public on company’s website

Timeline:

Year	Disclosure	Notes
2026	First report due	Deadline: Jan 1, 2026
2028	Second report due	Continues every two years

What To Do Now

Here’s your checklist if you’re likely subject to SB 253 or SB 261:

Confirm revenue thresholds ($500M or $1B+)
Assess current GHG data collection capabilities
Identify emission data gaps (especially Scope 3)
Assign internal owners for climate risk reporting
Choose standards (GHG Protocol, TCFD, ISSB)
Set up a timeline tracker aligned to these dates
Prepare for assurance provider engagement (SB 253)

Set up an internal SB 253 and SB 261 timeline tracker to stay ahead of deadlines and prepare for assurance provider engagement. Contact us for a walkthrough or book a demo.