California's SB 253 and SB 261:What Every Business Needs to Know Before the Deadline

ARTICLE 1 OF 2  |  REGULATORY COMPLIANCE  |  SB 253 / SB 261

You May Not Be Directly Covered — But Your Customers Are. Here Is Why That Changes Everything.

Published: March 2026   |   Reading time: 8 minutes   |   Topics: SB 253, SB 261, California climate disclosure, GHG reporting, climate risk, ESG compliance

WHY IT MATTERS

If your company does business with large corporations, sells into California, or generates more than $500 million in annual revenue anywhere in the United States, you need to understand two California laws that are reshaping corporate climate reporting in 2026 — and beyond.

Senate Bill 253 and Senate Bill 261, collectively known as California's Climate Accountability Package, represent the most far-reaching mandatory corporate climate disclosure regime enacted in US history. They do not apply only to California-based companies. They apply to any business that crosses their revenue thresholds and conducts business in the state — a standard that captures thousands of US and multinational corporations operating across every industry.

But here is the dimension that most companies are not yet preparing for: even businesses that fall below the direct compliance thresholds are already feeling the effect. Covered companies are required to report their Scope 3 greenhouse gas emissions — the emissions generated throughout their entire value chain — beginning in 2027. That means your customers are going to ask you for your emissions data. And if you cannot provide it, you risk losing contracts.

THE NUMBER TO KNOW

SB 253 is estimated to affect more than 5,000 US companies. Together, SB 253 and SB 261 cover businesses representing the vast majority of US corporate economic activity in California. And through Scope 3 supply chain requirements, their reach extends to tens of thousands more.

WHAT IT IS

SB 253: The Climate Corporate Data Accountability Act

Signed into law in October 2023 and administered by the California Air Resources Board (CARB), SB 253 requires large corporations doing business in California to publicly disclose their annual greenhouse gas (GHG) emissions across all three scopes of the GHG Protocol.

Requirement	Details
Who Must Comply	Business entities with total annual global revenues exceeding $1 billion that do business in California. This includes US and non-US entities.
Scope 1 & 2 Reporting	First reporting year covers FY2025 emissions. Initial deadline: August 10, 2026 (CARB proposed). Reported to CARB's digital platform.
Scope 3 Reporting	First reporting year covers FY2026 emissions. First report due 2027. 45 days after Scope 1/2 report.
GHG Protocol Standard	All disclosures must conform to GHG Protocol Corporate and Value Chain (Scope 3) standards.
Assurance Required	Limited assurance required from 2026. Reasonable assurance required from 2030.
Penalties	Up to $500,000 per entity per year for violations or material misstatements.

SB 261: The Climate-Related Financial Risk Act

SB 261 casts an even wider net in terms of the number of companies covered. It requires affected businesses to publicly disclose the climate-related financial risks they face and the measures they have taken — or plan to take — to reduce and adapt to those risks. The disclosure must be published on the company's public website and is aligned with the Task Force on Climate-related Financial Disclosures (TCFD) framework and ISSB standards.

Requirement	Details
Who Must Comply	Business entities with total annual global revenues exceeding $500 million that do business in California.
Report Content	Climate-related financial risks (physical and transition risks); risk assessment process; strategies and measures to reduce and adapt to identified risks.
Reporting Frequency	Biennial (every two years).
Public Availability	Report must be posted publicly on the company's website.
Framework Alignment	Consistent with TCFD / ISSB S2 / CSRD frameworks. Companies with existing TCFD-aligned reports may leverage prior work.
Current Status	Statutory deadline was January 1, 2026. Enforcement temporarily paused by a Ninth Circuit injunction (November 2025) while a legal challenge by the US Chamber of Commerce proceeds. CARB will announce a new compliance date following the appeal's resolution.
Penalties	Up to $50,000 per entity per year.

ON THE LEGAL STATUS OF SB 261

Enforcement of SB 261 is currently paused due to a Ninth Circuit Court of Appeals injunction issued in November 2025, following a legal challenge by the US Chamber of Commerce and other business groups. This does not repeal the law. CARB has confirmed it will issue a revised compliance date once the appeal is resolved. Companies should use this period to prepare — not to delay.

The Scope 3 Ripple Effect: Why Suppliers Cannot Afford to Wait

The most strategically significant element of SB 253 is its Scope 3 requirement. For covered companies, Scope 3 emissions — which include all upstream and downstream value chain emissions — typically represent between 70 and 90 percent of total corporate GHG footprint. This means covered companies will need data from every material supplier in their value chain to report accurately.

This is not a hypothetical future scenario. Large companies covered by SB 253 are already issuing supplier surveys, RFP questionnaires, and procurement requirements asking vendors to disclose their emissions. Companies that cannot provide verified, credible emissions data risk being deprioritized in procurement decisions or removed from approved vendor lists entirely.

The message for mid-market companies — even those well below the $1 billion revenue threshold — is direct: Scope 3 data requests from your customers are not going away. Preparing now is both a compliance risk mitigation strategy and a competitive differentiator.

• Understand your Scope 1, 2, and 3 GHG emissions baseline.

• Implement a defensible GHG accounting methodology aligned with the GHG Protocol.

• Build the internal data infrastructure needed to respond to customer data requests.

• Prepare for third-party assurance as a market expectation, not just a regulatory requirement.

• Align your disclosures with TCFD and ISSB S2 standards to satisfy multiple stakeholder requirements at once.

HOW ECOVANTAGE SUPPORT WORKS WITH YOU

EcoVantage Support: Your SB 253 and SB 261 Readiness Partner

EcoVantage Support provides end-to-end advisory services to help businesses understand, prepare for, and comply with California's climate disclosure requirements. Whether you are directly covered by SB 253 or SB 261, or a supplier facing Scope 3 data requests from your customers, our team brings the regulatory expertise, technical rigor, and practical implementation experience to get you ready.

Our SB 253 & SB 261 Deliverables

• Determine definitively whether your company is directly covered by SB 253 ($1B+ revenue) and/or SB 261 ($500M+ revenue) and what the compliance obligations mean for your business.Applicability Assessment:

• Build a fully GHG Protocol-compliant greenhouse gas emissions inventory for Scope 1 (direct emissions) and Scope 2 (purchased energy), ready for CARB reporting and third-party assurance.Scope 1 & 2 GHG Inventory:

• Identify material Scope 3 categories for your industry, design a data collection strategy, and build your Scope 3 inventory ahead of the 2027 reporting deadline — so you are not scrambling in year two.Scope 3 Emissions Assessment:

• Develop a comprehensive, TCFD/ISSB S2-aligned climate risk report covering physical risks, transition risks, your risk assessment process, and adaptation and mitigation strategies.Climate-Related Financial Risk Report (SB 261):

• Prepare your GHG data, methodologies, and documentation for limited assurance (required from 2026) and future reasonable assurance (required from 2030).Assurance Readiness:

• Help companies below the direct compliance thresholds build the emissions data and documentation needed to respond to customer data requests — protecting critical commercial relationships.Supplier Scope 3 Response Support:

• Ongoing monitoring of CARB rulemaking, SB 261 litigation developments, and SEC and CSRD alignment guidance, so your compliance approach stays current.Regulatory Monitoring & Strategy Updates:

ECOVANTAGE INSIGHT

The companies that will experience the least disruption from California's climate disclosure laws are the ones that start now. A GHG inventory built in advance of a regulatory deadline becomes a strategic asset — it informs decarbonization priorities, strengthens procurement negotiations, improves ESG ratings, and signals credibility to investors and lenders. Compliance cost and strategic value are not mutually exclusive.

The August 2026 Deadline Is Closer Than It Looks

The CARB-proposed deadline for your first SB 253 Scope 1 and 2 disclosure — covering your 2025 fiscal year emissions — is August 10, 2026. Building a credible, assurance-ready GHG inventory takes time. Most organizations need six to nine months of preparation to get it right. If you have not started, now is the moment to act.

EcoVantage Support offers a complimentary SB 253 / SB 261 Readiness Assessment to help you understand exactly where you stand, what is required, and what a clear path to compliance looks like for your business.

→  Contact EcoVantage Support: hello@ecovantagesupport.com

RELATED TOPICS: SB 253 compliance  |  SB 261 climate risk disclosure  |  California GHG reporting requirements  |  Scope 3 emissions reporting  |  California climate disclosure law  |  climate-related financial risk reporting  |  CARB GHG reporting  |  TCFD reporting  |  sustainability consultant  |  ESG compliance 2026

ARTICLE 2 OF 2  |  REGULATORY COMPLIANCE  |  SB 253 / CSRD / SEC

SB 253, CSRD, and the SEC Climate Rules:

A Plain-English Comparison Every US Sustainability Leader Needs

Three Overlapping Regimes, One Strategic Decision — How to Stop Treating Each Law Separately and Build a Unified Compliance Approach

Published: March 2026   |   Reading time: 10 minutes   |   Topics: SB 253, CSRD, SEC climate disclosure, ISSB S2, TCFD, ESG compliance framework, climate reporting requirements

WHY IT MATTERS

Ask a corporate sustainability leader what keeps them up at night in 2026, and the answer is almost always some version of the same problem: too many disclosure regimes, too little time, and teams that are stretched beyond their capacity trying to understand which rules apply, which deadlines are real, and whether yesterday's TCFD report is still good enough for today's requirements.

The answer is almost certainly no — and understanding why requires stepping back and mapping the landscape clearly.

Three major climate disclosure frameworks are currently shaping what US companies must report, when, and to whom: California's SB 253, the European Union's Corporate Sustainability Reporting Directive (CSRD), and the now-paused US Securities and Exchange Commission (SEC) climate disclosure rule. Each targets a different set of companies, requires a different level of detail, and operates on a different timeline. But they share a core architecture — and companies that understand the overlaps will spend significantly less money complying with all three than those that treat them as separate workstreams.

THE STRATEGIC OPPORTUNITY

The good news is that SB 253, CSRD, and the ISSB standards that informed the original SEC rule were all designed to converge around the same underlying frameworks: the GHG Protocol and TCFD/ISSB. A well-structured compliance program can satisfy multiple regimes from a single, well-governed data foundation — if it is designed with convergence in mind from the start.

WHAT EACH LAW REQUIRES

A Side-by-Side Comparison

The table below maps the three frameworks across six dimensions that matter most to US sustainability teams in 2026.

Dimension	SB 253 (California)	CSRD (EU)	SEC Climate Rule (US)
Who Must Comply	US & non-US entities with >$1B global revenue doing business in California	Large EU companies; non-EU companies with >€150M EU net turnover and a large EU subsidiary/branch	US-listed public companies (SEC registrants). Currently paused — not yet in effect.
What Is Disclosed	Scope 1 & 2 GHG emissions (2026); Scope 3 (2027). GHG Protocol required.	Full sustainability reporting across ESRS topics: climate (ESRS E1), social, governance, biodiversity, and double materiality.	Climate-related risks and opportunities; Scope 1 & 2 GHG (Scope 3 if material); climate targets and transition plan.
Underlying Framework	GHG Protocol (mandatory)	ESRS (European Sustainability Reporting Standards); GHG Protocol for emissions; TCFD architecture for climate	TCFD architecture; GHG Protocol for emissions data; ISSB S2 alignment
Key 2026 Deadline	August 10, 2026 (proposed Scope 1 & 2 first report — CARB). Active.	Large non-NFRD EU companies report on FY2025 in 2026. Non-EU companies: FY2028 (report in 2029).	Paused. SEC voted in 2025 to withdraw its defense of the rule. No active compliance deadline in 2026.
Third-Party Assurance	Limited assurance required from 2026; reasonable assurance from 2030.	Limited assurance required initially; transition to reasonable assurance planned.	Would have required attestation for Scope 1 & 2 disclosures. N/A while paused.
Penalties / Enforcement	Up to $500,000/year (SB 253). Up to $50,000/year (SB 261). Enforced by CARB.	Enforced by EU member state regulators. Scope and fines vary by jurisdiction.	N/A while paused. Rule would have been enforced by the SEC.

What This Means in Practice: The Framework Convergence Opportunity

The comparison above reveals something important: despite being authored by three different regulatory bodies in three different jurisdictions, SB 253, CSRD, and the SEC rule were all built on the same conceptual scaffolding — the GHG Protocol for emissions measurement and TCFD for climate risk disclosure.

This is not a coincidence. Regulators globally collaborated under the International Sustainability Standards Board (ISSB) to establish a common baseline, and ISSB's standards — particularly IFRS S2 for climate — have been formally incorporated or referenced by each of these regimes.

What this means for your sustainability program is profound: the core data you need to comply with SB 253 is largely the same data that forms the climate pillar of CSRD. A rigorous TCFD-aligned climate risk report — required under SB 261 — directly satisfies ISSB S2 and would have satisfied the SEC rule's risk disclosure requirements. The companies that build their programs around this shared foundation will not only comply more efficiently; they will produce better, more credible disclosures.

The Three-Layer Compliance Architecture

We recommend thinking about climate disclosure compliance in three layers:

• A GHG Protocol-compliant Scope 1, 2, and 3 emissions inventory, with defensible methodology documentation and assurance-ready data governance. This is the non-negotiable core for SB 253 and CSRD (ESRS E1), and was central to the SEC rule.Layer 1 — GHG Data Foundation:

• A TCFD/ISSB S2-aligned assessment of physical and transition climate risks and opportunities, including scenario analysis. This directly fulfills SB 261 and the climate risk requirements of both CSRD and the SEC rule.Layer 2 — Climate Risk Assessment:

• A net zero strategy, decarbonization pathway, and target framework (aligned with SBTi where relevant) that transforms your compliance disclosures into a forward-looking climate strategy that satisfies sophisticated investor, customer, and regulatory audiences simultaneously.Layer 3 — Strategic Narrative:

A CRITICAL NOTE ON THE SEC RULE

In February 2025, the SEC voted to withdraw its defense of the climate disclosure rule finalized in March 2024, effectively placing the rule on hold indefinitely under the current administration. As of March 2026, there is no active SEC compliance deadline for climate-related financial disclosures. However, companies that are SEC registrants should note that voluntary disclosure expectations from institutional investors remain high — and that the rule's architecture is closely aligned with ISSB S2, which is being adopted by jurisdictions worldwide.

Who Needs to Worry About What — Right Now

The practical question for most US companies in 2026 is: which of these frameworks requires action from me this year? The answer depends on your revenue, your business footprint, and your ownership structure.

Company Profile	Your Priority Action in 2026
>$1B revenue, doing business in California	SB 253 CRITICAL: Begin Scope 1 & 2 GHG inventory immediately. August 10, 2026 proposed deadline. Engage assurance provider.
>$500M revenue, doing business in California	SB 261 IMPORTANT: Prepare TCFD/ISSB S2-aligned climate risk report. Enforcement paused — use this window to prepare before CARB issues new deadline.
Below thresholds but supplying companies above them	SUPPLY CHAIN CRITICAL: Your customers will request Scope 3 emissions data. Build your GHG baseline and Scope 3 data-sharing capability now.
Large EU subsidiary or >€150M EU net turnover	CSRD COMPLIANCE: EU operations face CSRD reporting on FY2025 (due 2026) or FY2028 (due 2029) depending on company size. Start double materiality and ESRS gap assessment.
SEC-listed public company	MONITOR: SEC rule is paused. Focus on voluntary ISSB S2-aligned disclosures to satisfy investor demands. Prepare for potential rule reinstatement.
All of the above	INTEGRATED STRATEGY: Build a unified compliance architecture across all regimes — one GHG data foundation, one climate risk assessment, one strategic narrative. The most efficient and resilient approach.

HOW ECOVANTAGE SUPPORT WORKS WITH YOU

EcoVantage Support: Multi-Framework Climate Compliance Advisory

EcoVantage Support specializes in helping companies design and implement climate disclosure programs that satisfy multiple regulatory frameworks simultaneously — without duplicating effort, overspending on consultants, or building siloed workstreams that cannot talk to each other.

Our multi-framework approach is built around the same convergence logic described above: a single, well-governed GHG data foundation and TCFD/ISSB S2-aligned climate risk framework that can satisfy SB 253, SB 261, CSRD, ISSB, and future SEC requirements from one integrated program.

Our Multi-Framework Deliverables

• A clear, documented assessment of which climate disclosure regimes apply to your business — SB 253, SB 261, CSRD, ISSB, SEC — with prioritized compliance obligations and timelines.Regulatory Applicability Matrix:

• A single, GHG Protocol-compliant greenhouse gas emissions inventory structured to serve SB 253 reporting, CSRD ESRS E1 disclosure, and ISSB S2 simultaneously.Integrated GHG Inventory (Scope 1-3):

• A comprehensive physical and transition climate risk report aligned to TCFD and ISSB S2 frameworks — simultaneously satisfying SB 261, CSRD climate requirements, and investor-grade disclosure expectations.TCFD / ISSB S2 Climate Risk Assessment:

• A structured gap assessment mapping your current disclosures against SB 253, SB 261, CSRD (ESRS E1), and ISSB S2 requirements — identifying exactly what you have, what you need, and in what sequence.Multi-Framework Disclosure Gap Analysis:

• Double materiality assessment, ESRS gap analysis, and CSRD-aligned sustainability report development for companies with EU operations or EU reporting obligations.CSRD Readiness Program:

• Documentation, data governance protocols, and methodology review to prepare your GHG disclosures for limited assurance (SB 253, 2026) and reasonable assurance (SB 253, 2030; CSRD transition).Assurance Preparation:

• Where climate disclosure obligations intersect with science-based target setting (SBTi), decarbonization planning, and internal carbon pricing — we ensure your compliance program also drives your climate strategy forward.Net Zero Strategy Integration:

Stop Managing Climate Compliance Frameworks One at a Time

The companies making the smartest investments in climate disclosure right now are not treating SB 253, CSRD, and ISSB as three separate projects. They are building a single, rigorous foundation — one GHG inventory, one risk assessment, one strategic narrative — that serves all three.

EcoVantage Support can help you design that integrated program, starting with a no-cost Multi-Framework Climate Disclosure Assessment. We will map your current state against every applicable regime, identify your critical gaps, and give you a clear, sequenced action plan.

→  Contact EcoVantage Support: hello@ecovantagesupport.com

RELATED TOPICS: SB 253 vs CSRD  |  California climate disclosure law  |  CSRD compliance for US companies  |  SEC climate disclosure rule status  |  ISSB S2 reporting  |  TCFD reporting requirements  |  multi-framework ESG compliance  |  GHG emissions reporting  |  climate risk assessment  |  sustainability consultant  |  climate corporate accountability act  |  ESG regulatory compliance 2026