Who has to report what in 2027: CSRD, ISSB, California, and UK SRS after the Omnibus
Updated: Sep 6
In 2027, mandatory sustainability reporting begins or expands for four groups: EU companies above the new Omnibus thresholds, US companies above $1 billion doing business in California, UK-listed companies, and the largest firms in Japan and Australia under ISSB-based national rules. The EU's Corporate Sustainability Reporting Directive (CSRD) now applies to companies with more than 1,000 employees and more than €450 million in net turnover. Those cutoffs were set by Directive (EU) 2026/470, the Omnibus, which has been in force since March 18, 2026. The ISSB is the International Sustainability Standards Board, whose two disclosure standards most regimes outside the EU have copied into national law. The Omnibus changed which regulator sets a multinational's requirements far more than it reduced them, and for many large groups the first regime to bind in 2027 is California's SB 253, the state's emissions-reporting law, or an ISSB-based national rule.
The Omnibus delivered real deregulation for mid-size European companies and far less relief for the multinationals the political fight was ostensibly about. Estimates presented around the European Parliament's final vote put the remaining CSRD population at 5,100 to 7,800 companies, reporting 60 to 70 percent fewer datapoints than the original standards demanded. A business that falls below the CSRD thresholds usually remains inside mandatory reporting, because a group large enough to approach the EU cutoffs is typically large enough to cross a revenue, asset, or listing threshold in another jurisdiction. Several of those other regimes reach their first reporting year in 2027.
What CSRD still requires after the Omnibus
CSRD still demands a double-materiality sustainability statement under the European Sustainability Reporting Standards (ESRS) from EU companies above the 1,000-employee and €450 million thresholds. Double materiality means reporting both what climate does to the company and what the company does to the world. Wave-one companies, the large listed businesses that began reporting under the original directive, publish their fiscal 2026 reports in 2027. Newly scoped, wave-two companies begin their first covered year, fiscal 2027, during that same calendar year. The Omnibus lets member states exempt any wave-one company that falls below the new cutoffs for fiscal 2025 and 2026. Some familiar wave-one reporters will therefore stop publishing after their fiscal 2025 or 2026 statement.
Every company above the new thresholds prepares its next report against standards revised in July 2026. The European Commission adopted the revised, slimmer ESRS in a delegated act (EU secondary legislation the Commission adopts directly) on July 3, 2026. The practical effect is that a wave-two company cannot treat a 2025 wave-one report as its template, since the datapoint set underneath it has been rewritten. Non-EU parent groups with large EU revenue keep a separate obligation that starts on a later schedule than the wave-one and wave-two dates.
Three of the four regimes place a first cohort or a first expansion into 2027, while CSRD's own newcomers publish nothing until 2028. Japan's new national standards and Australia's second reporting group produce their first mandatory reports during 2027. California adds scope 3 (emissions from the value chain around a company) in the same year, and the UK Sustainability Reporting Standards (UK SRS) are proposed to take their first mandatory year then as well.
Figure 1. Who has to report what in 2027 across CSRD, California SB 253 and SB 261, UK SRS, Japan, Australia, and Singapore: scope thresholds, what happens in 2027, and current status. Analysis: Gasilov Group, our cross-reference of the statutes and regulator publications linked in this post, current as of August 2026.
A group-level scoping pass converts the dates in Figure 1 into three concrete moves for a reporting, legal, or finance team. First, assign every legal entity and listing to a regime and a first covered period, because the obligations attach at entity and listing level (a listing on Tokyo's top market segment or a Delaware subsidiary selling into California each triggers its own obligation). Second, let the earliest binding regime set the group's emissions data architecture. A scope 1 and 2 baseline (covering a company's own operations and purchased energy) built for California this year is the same baseline that a Japanese filing, an Australian sustainability report, and a UK listing will use next year. A program built to the loosest regime, by contrast, gets rebuilt a second time once a stricter regime's deadline arrives. Third, calendar the two finalizations that can still move dates: the California Air Resources Board's (CARB's) rulemaking for 2027 reporting and the UK Financial Conduct Authority's (FCA's) autumn policy statement.
The personalized version of this exercise already exists as a free self-check: our ESG Regulatory Readiness Assessment takes headquarters, listing, headcount, revenue, EU presence, and California activity, and returns the regimes that apply with a deadline timeline. It is maintained against the same primary legal instruments and deadline dates.
What California requires in 2026 and 2027
California's SB 253 requires US companies above $1 billion in annual revenue doing business in the state to report scope 1 and 2 emissions in 2026 and to add scope 3 in 2027. SB 261's climate-risk report, for companies above $500 million, is blocked for now by a federal court order.
CARB approved its initial regulation on February 26, 2026, setting the first scope 1 and 2 deadline at August 10, 2026. In June the agency announced that it intends to move that date to November 10, 2026 through an expedited rulemaking, a shortened procedure for adopting the change. CARB's July 27, 2026 15-day notice writes November 10 into the regulatory text as the ongoing annual deadline. That schedule has already moved once and can move again. First-year expectations are deliberately modest, and CARB has said that good-faith reports built from data a company already held or was collecting as of December 2024 will satisfy it. Limited assurance (an external review less rigorous than a full audit) on scope 1 and 2 begins with 2027 reporting.
The scope 3 rules for 2027 remain an open rulemaking question at CARB. At its July 21, 2026 workshop the agency dropped the all-fifteen-at-once option and proposed a category-based phase-in: five of the fifteen value-chain categories required in 2027 (purchased goods and services, fuel- and energy-related activities, waste, business travel, and employee commuting), the rest voluntary, with a formal draft expected in fall 2026 and a 45-day comment period to follow. Until the second regulation is adopted, the 2027 scope 3 requirement remains a proposal.
SB 261 is the stalled half of the California package, and its first reports were due January 1, 2026. A federal appeals court, the Ninth Circuit, enjoined enforcement on November 18, 2025. That order bars the state from enforcing the law while the appeal proceeds. Argument was heard on January 9, 2026, and a decision is still pending. CARB has committed to setting an alternate reporting date once the appeal resolves. That leaves a company above the SB 261 revenue threshold holding a drafted climate-risk report with no enforceable date to publish it against. On a scoping memo, SB 253 belongs on the work plan with a deadline, and SB 261 belongs on the watch list with a trigger.
Where the UK and the ISSB jurisdictions start in 2027
The UK and the leading ISSB jurisdictions each place a first cohort of reporters into 2027. The FCA proposes mandatory UK SRS climate reporting for periods beginning January 1, 2027. Japan's largest listed companies file first in mid-2027, and Australia's second group lodges its reports in late 2027.
The UK standards themselves are finished: the Department for Business and Trade published the final UK SRS S1 and S2 on February 25, 2026 for immediate voluntary use, closely tracking the ISSB originals. S2 covers climate, and S1 covers the wider sustainability topics. Under the FCA's consultation CP26/5, climate disclosure against UK SRS S2 would be mandatory. Scope 3 would run from the second year on a comply-or-explain basis, under which a company either reports or explains why it has not. The wider S1 topics would follow on the same basis from 2029. Which companies must report stays proposed until the FCA's policy statement, expected in autumn 2026. The government separately holds an undated decision on extending the standards to large private companies.
Japan moves first among the ISSB adopters, and its version carries direct legal force, because the disclosures go inside the annual securities report itself. Under the Financial Services Agency's published timetable, Prime Market companies (the Tokyo Stock Exchange's top segment) with market capitalization of ¥3 trillion or more report under the SSBJ standards, Japan's adaptation of the ISSB originals. Their first mandatory year is the fiscal year ending March 31, 2027. For the March year-ends most large Japanese companies use, the first mandatory filings fall due in June 2027, with a lower market-cap tier following a year later.
Australia's regime is already statutory and phased, with its second group defined by meeting two of three tests: A$200 million in consolidated revenue, A$500 million in assets, or 250 employees. First reporting periods for that group begin on July 1, 2026. For the June fiscal year-ends most Australian groups use, that produces first sustainability reports lodged with the regulator in the second half of 2027.
Singapore demonstrates how far a scoping memo written in 2024 can now diverge from the dates that apply today. Its large non-listed companies, first scheduled for fiscal 2027 when the reporting timeline was announced, were deferred to fiscal 2030 by ACRA, the corporate regulator, and the exchange in August 2025. Plenty of compliance calendars written before that change still show the old date.
The IFRS Foundation, the ISSB's parent body, counts 39 jurisdictions, together about 60 percent of global GDP, adopting or moving toward its standards, a total that has kept growing even as individual national dates slip. As a result, a scoping answer that addresses CSRD, California, the UK, and the leading ISSB adopters covers the bulk of the exposure, with the remaining jurisdictions adopting the same ISSB-based standards on later dates.
The ESRS datapoint count is the input that has already changed: the Commission adopted the revised standards on July 3, 2026, and they apply to fiscal 2027, with early application for fiscal 2026 permitted once the act enters into force.
If you are not sure where your reporting obligations begin across these regimes, the ISSB and California Readiness Review, a two-week diagnostic, is built to answer that question. If you already know what you need, get in touch and we can scope it.
Seyfi Gasilov is partner for Sustainability Reporting & Governance at Gasilov Group, where he works on CSRD and ESRS compliance, ISSB, internal controls, and supply-chain due diligence. Meet our partners →
Frequently Asked Questions (FAQ)
Do non-EU parent companies still have to report under CSRD?
Yes, on a separate schedule: a non-EU parent is in scope when its EU net turnover exceeded €450 million in each of the last two years and it also has an EU subsidiary or branch with more than €200 million in turnover. No employee test applies. Its first report covers fiscal year 2028 and is then published during the course of 2029.
What replaces CSRD for the companies the Omnibus removed?
A voluntary standard for smaller companies (the VSME) sets the maximum that in-scope customers may demand from value-chain partners with fewer than 1,000 employees. Reporting pressure accordingly continues through customer contracts even where the legal mandate ended.
