US Climate Disclosure in 2026: California SB 253, SB 261, and the SEC Rule

For companies that operate in the United States, the center of gravity for mandatory climate disclosure has shifted from Washington to Sacramento. The federal SEC climate rule that dominated planning in 2024 is now in retreat, while California's SB 253 and SB 261 have moved into implementation and will reach thousands of companies far beyond the state's borders. If you do business in California and clear the revenue thresholds, the relevant deadlines are close, and the data lift, especially for emissions across your value chain, is the part that takes the longest to build. This article sets out who is covered, what each law requires, the first reporting dates, where CARB stands on implementation, and the current legal status of the SEC rule.

The theme running through all three is that scope of coverage is defined by revenue and by doing business in California, not by whether a company is headquartered there. A privately held manufacturer in the Midwest that sells into California can be squarely in scope. Understanding the thresholds and the reporting calendar is the first step toward not being caught flat footed.

SB 253: the Climate Corporate Data Accountability Act

SB 253 is the emissions reporting law. It applies to US entities with total annual revenues in excess of one billion dollars that do business in California. Covered companies must disclose their greenhouse gas emissions using the widely adopted GHG Protocol categories: Scope 1 (direct emissions), Scope 2 (purchased energy), and Scope 3 (value chain emissions).

The phase in is staged by scope. Per CARB, Scope 1 and Scope 2 emissions reporting begins in 2026, and Scope 3 reporting begins in 2027. CARB has also acknowledged that companies need lead time to stand up data collection, so for the first report it stated it would exercise enforcement discretion, allowing entities to submit Scope 1 and Scope 2 figures based on information they already have or were already collecting, provided they make a good faith effort.

SB 261: climate-related financial risk reporting

SB 261 is the risk disclosure law, and it sits at a lower revenue bar. It applies to US entities with annual revenues of $500 million or more that do business in California. Rather than an emissions inventory, SB 261 requires a climate-related financial risk report prepared in line with an established framework such as the recommendations of the Task Force on Climate-related Financial Disclosures or the IFRS S2 standard, and it is filed on a biennial cadence.

SB 261's statutory first deadline was January 1, 2026. That date, however, has been overtaken by litigation, which we cover below. Even with enforcement paused, the substance of an SB 261 report, a clear account of how climate risk affects the business and how the company is managing it, depends on having credible underlying energy and emissions data to reference. Companies that treat it purely as a narrative exercise tend to produce reports that do not withstand scrutiny.

First reporting dates and CARB implementation status

CARB, the California Air Resources Board, is the agency writing and enforcing the rules. It approved the initial implementing regulation on February 26, 2026. Because that adoption came only months before the original filing window, CARB deferred the first SB 253 reporting deadline to November 10, 2026, a three month move from the August 10, 2026 date it had previously set, to give reporting entities more time after the regulation was final.

The practical reading of the CARB calendar: the first SB 253 emissions report is due in the back half of 2026, covers Scope 1 and 2, and comes with a good faith enforcement posture for that first cycle. Scope 3 follows in the 2027 cycle. Companies should not read the enforcement discretion as a reason to delay, because the data infrastructure that produces a defensible number takes months to assemble, and the discretion applies to the first report only.

The SB 261 litigation and where it stands

SB 261's rollout has been disrupted by a First Amendment challenge brought by the US Chamber of Commerce and other business groups, who argue the laws compel speech on contested policy questions. On November 18, 2025, the Ninth Circuit Court of Appeals granted an injunction pausing enforcement of SB 261 while it reviews the appeal. Notably, the injunction applied to SB 261 only and did not extend to SB 253.

In response, CARB issued an enforcement advisory on December 1, 2025 stating it would not enforce the SB 261 January 1, 2026 deadline against covered entities while the injunction remains in place, and that it would set an alternate reporting date after the appeal is resolved. The Ninth Circuit heard oral argument on January 9, 2026, and as of mid 2026 a final decision was still pending, leaving SB 261 enforcement paused but the underlying obligation intact. If the injunction is lifted, compliance duties can resume, so companies in scope should keep their SB 261 reporting on track rather than treating the pause as a cancellation.

The SEC climate rule: adopted, then abandoned

The federal picture is moving in the opposite direction from California. The SEC adopted its climate-related disclosure rule in March 2024, but the agency stopped defending it in 2025, and on May 29, 2026 the Commission proposed to rescind the climate-related disclosure rules in their entirety. The proposal was published in the Federal Register on June 3, 2026, with a public comment period, and the Commission's stated rationale is that the 2024 rules exceeded its statutory authority and were unsound as policy.

For planning purposes, treat the SEC rule as effectively dormant. There are no active federal compliance dates to build toward, and a final rescission would remove it entirely. That does not reduce the pressure on large companies, because California's regime, along with investor expectations and other jurisdictions' rules, keeps mandatory-quality climate data firmly on the agenda. The federal retreat mainly means California, not the SEC, is now the binding constraint for US operations.

• SB 253 applies at over $1 billion in revenue and covers Scope 1, 2, and 3 emissions, phased 2026 then 2027.
• SB 261 applies at over $500 million in revenue and covers climate-related financial risk, currently paused by injunction.
• CARB adopted its initial regulation on February 26, 2026 and deferred the first SB 253 deadline to November 10, 2026.
• The SEC climate rule has no active compliance dates and is the subject of a 2026 rescission proposal.
• Doing business in California, not headquarters location, determines whether a company is in scope.

How MartinAI helps

Whether the binding requirement is SB 253, SB 261, or a customer's own supply chain questionnaire, the bottleneck is the same: assembling accurate, auditable energy and emissions data from messy source records. MartinAI ingests utility bills and meter data across electricity, gas, and other fuels, validates every read, and builds a clean, whole-entity record that maps directly to Scope 1 and Scope 2 under the GHG Protocol categories. That removes the manual reconciliation that otherwise consumes weeks before a single number is reportable.

For Scope 3, the same validated foundation gives you a defensible activity baseline to extend into value chain categories, so the 2027 cycle is a build on top of existing data rather than a cold start. And because SB 261 risk reporting relies on credible metrics to support its narrative, the structured emissions and consumption record MartinAI produces gives your climate risk report real numbers to stand on. One validated dataset serves the emissions filing, the risk report, and investor requests, with a clear trail back to source documents for assurance. The point is to end the manual data wrangling, not to add another tool.

Conclusion

In 2026 the operative US climate disclosure rules are California's, not the SEC's. SB 253 pulls in companies over $1 billion in revenue with a first emissions report due November 10, 2026 and Scope 3 following in 2027, while SB 261 reaches companies over $500 million with a risk report that is currently paused by a Ninth Circuit injunction but not repealed. The SEC rule, meanwhile, is on its way out. The companies that handle this well are the ones that stop treating disclosure as a year end reporting event and start treating it as a data pipeline: validated, auditable, and ready regardless of which deadline moves next.