The sustainability disclosure obligations companies must meet are splitting into rules across multiple jurisdictions as 2026 begins. The U.S. Securities and Exchange Commission (SEC) climate disclosure rule has been withdrawn, while California's disclosure regulations and the systems of countries that have adopted the International Sustainability Standards Board (ISSB) standards are moving into the implementation stage. The days when meeting a single standard was enough are over, and the system now requires satisfying different demands separately in each region where a company operates. The Korea Accounting Institute has also decided, amid the same trend, to finalize and announce its sustainability disclosure standards in January 2026.
One axis driving the regulatory fragmentation is state-level legislation in the United States. California's climate disclosure law SB253 first requires companies with annual revenue above $1 billion (about 1.38 trillion won) to disclose Scope 1 and 2 emissions, and is designed to expand to Scope 3 at a later stage. August 10, 2026 has been set as the first reporting date, but the reporting method and detailed schedule will be determined through implementing regulations being drawn up by the California Air Resources Board (CARB). When those implementing regulations will be completed is not known.
SB261, another law in the same state, is in a different situation. The law sets the scope for climate-related financial risk reporting at companies with annual revenue exceeding $500 million (about 690 billion won), and its first reporting date was January 1, 2026. However, enforcement was provisionally suspended when the U.S. Court of Appeals for the Ninth Circuit issued a preliminary injunction on November 18, 2025. Even now that the scheduled date has passed, it remains unresolved whether the obligation must actually be met.
The scope of application is not drawn according to where a company is headquartered. Companies that generate revenue in California can be covered even if they are headquartered outside the United States. Under SB253, noncompliance carries fines of up to $500,000 a year.
On the ISSB axis, the timetable is tighter. The United Kingdom plans to make the UK Sustainability Reporting Standards (UK SRS), based on the ISSB standards, mandatory from the 2026 fiscal year, and Australia will begin a phased introduction over 2025-2026, starting with large listed companies and financial institutions. Canada also plans to apply its own ISSB-aligned standards (CSSB) from 2026, centered on listed companies. In Europe, pressure to adjust the Corporate Sustainability Reporting Directive (CSRD) and the Corporate Sustainability Due Diligence Directive (CS3D) is building against the backdrop of the omnibus discussions, but whether and when the adjustments will be finalized has not been confirmed.
The area where costs appear as actual figures is the Carbon Border Adjustment Mechanism (CBAM). The system, which entered its transition period in October 2023, has so far required only reporting of embedded emissions in imported goods, but from 2026 an obligation to purchase certificates will be added. Importers bringing covered goods such as steel, cement and aluminum into the EU will have to buy certificates linked to the price under the EU Emissions Trading System (ETS). It means emissions, once a reporting item, become a payment item.
Demands on disclosure quality have risen alongside. By the OECD's count, as of 2024, 81% of the listed companies with the largest market capitalization that disclosed sustainability information obtained third-party assurance. It means that going through external verification, in place of releasing self-calculated figures as they are, has become established practice for the majority. How many companies the statistic surveyed is not known.
The domestic schedule moves along three tracks. The Korea Accounting Institute's announcement finalizing the disclosure standards is expected in January, and the National Assembly has also signaled that bills related to introducing ESG disclosure will be proposed in the same month. By contrast, the Financial Services Commission's roadmap announcement may come later than the finalization of the standards. The Federation of Korean Industries has called for the roadmap to be released.
For companies, differing baselines by jurisdiction are themselves a compliance cost. When the scope of emissions calculation, reporting timing and level of verification diverge from region to region, producing multiple reports from a single set of data becomes difficult. Companies with California revenue, companies exporting steel and aluminum to the EU, and companies with listed affiliates in the United Kingdom, Australia and Canada are placed in a position of having to manage different timetables at the same time.
The dates that need checking have been laid out. The finalization of the domestic disclosure standards expected in January, the August 10, 2026 reporting deadline that hinges on CARB's implementing regulations, and the schedule for SB261, whose direction remains open after the Ninth Circuit's decision. How each of the three is resolved will determine the number and deadlines of the reports companies must prepare this year.
