SEC Climate Disclosure Requirements 2026:
What Mid-Market Companies Need to Know

The SEC Climate Disclosure Rule: What It Requires

In March 2024, the Securities and Exchange Commission finalized its landmark climate disclosure rule — the most significant expansion of corporate sustainability reporting in U.S. history. After years of comment periods and legal battles, the rule is now being phased in for public companies, with private company obligations following through supply chain pressures and state-level mandates.

The rule requires registrants to disclose material climate-related risks in their annual reports (Form 10-K) and registration statements. This isn't voluntary ESG reporting — it's enforceable federal securities law.

Core Disclosure Requirements

Under the SEC rule, covered companies must disclose:

• Governance: Board oversight of climate risks and management's role in assessing and managing them
• Strategy: Climate-related risks that have had, or are reasonably likely to have, a material impact on strategy, business model, or outlook
• Risk management: Processes for identifying, assessing, and managing climate-related risks
• Metrics and targets: Scope 1 and Scope 2 greenhouse gas emissions (for large accelerated filers); Scope 3 if material or included in a net-zero target
• Severe weather events: Financial impact of severe weather events and other natural conditions (if above a 1% threshold of certain line items)
• Carbon offsets: Use and costs of carbon offsets and renewable energy credits if material to climate targets

Phase-in Schedule

• FY2025
  Large Accelerated Filers (LAFs) — Climate Risk Disclosures Companies with public float ≥$700M must disclose climate risk governance, strategy, and risk management in their 10-K. GHG emission disclosures follow in FY2026.
• FY2026
  LAFs — Scope 1 & 2 Emissions + Accelerated Filers Climate Risk Large accelerated filers begin disclosing Scope 1 and Scope 2 GHG emissions (subject to limited assurance). Accelerated filers (public float $75M–$700M) begin climate risk disclosures.
• FY2027
  Accelerated Filers — Scope 1 & 2 + Non-Accelerated Filers Climate Risk Accelerated filers add GHG metrics. Non-accelerated filers begin climate risk disclosures. Scope 3 disclosures remain under review pending legal proceedings.
• FY2028
  Full Rollout for Smaller Reporting Companies All covered registrants fully subject to the rule. Assurance requirements escalate to reasonable assurance for LAFs.

EU Corporate Sustainability Reporting Directive (CSRD)

The EU's CSRD is broader, more prescriptive, and — for companies with EU operations — more immediately demanding than the SEC rule. It replaces the Non-Financial Reporting Directive (NFRD) and introduces the European Sustainability Reporting Standards (ESRS).

If your company has any EU subsidiaries, operations, or significant EU-listed securities, CSRD is likely on your compliance roadmap.

Who Does CSRD Cover?

What CSRD Requires

CSRD uses a "double materiality" framework — companies must report both:

• Financial materiality: How climate affects the company's finances
• Impact materiality: How the company's activities affect the climate

The European Sustainability Reporting Standards (ESRS) require detailed disclosures across climate, biodiversity, water, social, and governance topics. The climate standard (ESRS E1) requires full Scope 1, 2, and 3 emissions with a transition plan.

California SB 253 & SB 261: The U.S. State-Level Mandate

California didn't wait for federal action. Governor Newsom signed two landmark climate disclosure bills in October 2023 that create the broadest mandatory emissions reporting requirements for private companies in U.S. history.

These laws apply to private companies — something the SEC rule generally does not. If you do business in California and hit the revenue thresholds, you're covered.

SB 253 — Climate Corporate Data Accountability Act

Who it covers: Any company (public or private) that does business in California with total annual revenues exceeding $1 billion.

What it requires:

• Annual disclosure of Scope 1 and Scope 2 GHG emissions (beginning January 1, 2026 for FY2025 data)
• Annual disclosure of Scope 3 emissions (beginning January 1, 2027 for FY2026 data)
• Emissions must be reported to a state-designated disclosure organization (currently CARB-supervised)
• Third-party verification required — limited assurance for Scope 1/2, limited assurance for Scope 3

SB 261 — Climate-Related Financial Risk Act

Who it covers: Any company (public or private) that does business in California with total annual revenues exceeding $500 million.

What it requires:

• Biennial (every 2 years) climate-related financial risk report
• Report must align with TCFD (Task Force on Climate-Related Financial Disclosures) framework
• Must disclose physical risks and transition risks
• Report filed publicly with the state and posted on company website
• First reports due January 1, 2026

California vs. SEC: Key Differences

What to Report: Scope 1, 2, and 3 Emissions Explained

All three frameworks — SEC, CSRD, and California — use the GHG Protocol Corporate Accounting and Reporting Standard as the baseline methodology. This divides emissions into three "scopes" based on where they occur in your value chain.

The Scope 3 Challenge

For most mid-market companies, Scope 3 accounts for 65–90% of total emissions — yet it's the hardest to measure. The GHG Protocol identifies 15 categories of Scope 3 emissions, split between upstream (supply chain) and downstream (customers, end-of-life) activities.

Under California SB 253, Scope 3 reporting is mandatory starting FY2026. Under the SEC rule, it's required if your company has a climate target that includes Scope 3 (e.g., a "net zero by 2040" commitment). Under CSRD, it's fully mandatory with third-party verification.

Accepted Calculation Methods

• Spend-based method: Multiply supplier spend by economic intensity emission factors (easiest to implement, lower accuracy)
• Average data method: Use industry-average emission factors for specific activities (good for Scope 1/2 and some Scope 3)
• Supplier-specific method: Use actual emissions data from your suppliers (most accurate, requires supplier engagement)
• Hybrid method: Combine supplier-specific data where available with average data for gaps (recommended approach)

Penalties for Non-Compliance

These aren't voluntary frameworks with reputational risk as the only downside. All three regimes carry meaningful financial penalties — and California's apply to private companies starting in 2026.

Beyond Fines: Business Risk

Non-compliance carries costs that don't show up on the enforcement docket:

• Lender covenants: Major banks (JPMorgan, Bank of America, Goldman Sachs) are incorporating ESG metrics into credit agreements. Companies without defensible emissions data face covenant triggers.
• Customer contracts: Fortune 500 procurement teams are adding Scope 3 data requirements to vendor agreements. No data = no contract.
• M&A due diligence: PE firms and strategic acquirers now conduct ESG due diligence as standard. Undisclosed climate liabilities affect valuation.
• Insurance pricing: Climate-exposed assets without quantified risk profiles face higher premiums or coverage exclusions.

Does Your Company Need to File?

How Mid-Market Companies Should Prepare Now

The companies that will struggle most aren't those that lack data — they're those that start too late. Here's a practical playbook for getting compliant without building a 10-person sustainability department.

Phase 1: Baseline Measurement (Months 1–2)

• Inventory all Scope 1 sources: company-owned vehicles, on-site combustion (natural gas, diesel, propane), industrial processes, refrigerants
• Compile Scope 2 inputs: electricity bills for all facilities, data center power purchase agreements
• Identify top 3–5 Scope 3 categories by spend (use your ERP/AP data as a starting point)
• Choose a calculation methodology (EPA emission factors are the US standard; IPCC factors for global operations)
• Run your first baseline calculation to understand your emissions profile

Phase 2: Data Infrastructure (Months 2–4)

• Establish a repeatable data collection process — ideally pulling from utility APIs and ERP integrations
• Document your methodology (regulators and auditors will ask for this)
• Engage key suppliers on Scope 3 Category 1 (purchased goods) data sharing
• Map your reporting obligations by jurisdiction and set calendar reminders for filing deadlines
• Identify and engage a third-party verifier if required by your applicable regulations

Phase 3: Reporting and Verification (Months 4–6)

• Prepare draft disclosure aligned with applicable framework (SEC, CSRD, or CA CARB)
• Submit to third-party verifier for limited assurance review
• Integrate climate disclosures into annual report or file separately per regulation requirements
• Set up ongoing monitoring — emissions reporting is now annual (or biennial for SB 261)
• Consider setting a science-based reduction target (SBTi) to demonstrate commitment and manage future Scope 3 obligations

Frequently Asked Questions