Sustainability disclosure is shifting from a voluntary exercise to a legal obligation across the world's major economies. The European Union's Corporate Sustainability Reporting Directive (CSRD) is already producing its first reports, California's SB 253 and SB 261 begin bite in 2026, and a cluster of jurisdictions — Canada, Australia, Hong Kong and Mexico among them — are building rules around standards from the International Sustainability Standards Board (ISSB). The result, as IR Impact's Laurie Havelock describes it, is a reporting environment that is "more complex, but also more transparent, globally aligned and investor-focused."

The Global Shift to Mandatory ESG Reporting

For years, corporate sustainability reporting lived in a voluntary world of overlapping frameworks — TCFD, SASB, CDSB and GRI — that companies could adopt, adapt or ignore. That era is closing. Governments and securities regulators are now writing disclosure requirements into law, and the direction of travel is consistent: mandatory rules, standardized metrics, and alignment with a common global baseline.

The scale of the shift is visible in the EU alone. According to Worldfavor, a sustainability data platform, the CSRD extends mandatory reporting obligations to roughly 50,000 companies in the EU, corresponding to about 75% of EU companies' turnover. What was once the province of large listed firms is becoming a broad corporate compliance duty.

The economic rationale is not purely regulatory. A working paper from the European Corporate Governance Institute, which compiled a global dataset of mandatory ESG disclosure regimes, documents a positive effect of disclosure mandates on firm-level stock liquidity. The effects are strongest, the researchers found, where requirements are implemented by government institutions rather than on a comply-or-explain basis, and where they are coupled with strong enforcement. Firms with weaker information environments benefit most — supporting the view that ESG disclosure regulation improves the information environment and produces beneficial capital market effects.

Key Jurisdictions and Their New Reporting Rules

The landscape is fragmented but converging. The table below compares the major jurisdictions on the dimensions that matter most to a compliance or investor-relations team: what the rule is called, when it takes effect, what it covers, and how it relates to international standards.