What ISSB is
The International Sustainability Standards Board (ISSB), operating under the IFRS Foundation, issued its first two global sustainability disclosure standards in June 2023: IFRS S1 (general sustainability-related disclosures) and IFRS S2 (climate-related disclosures). Together they're designed as a single, investor-focused baseline, consolidating what had been a fragmented landscape of voluntary frameworks (TCFD, SASB, and others) into one coherent structure.
What IFRS S1 covers
General requirements for disclosing sustainability-related risks and opportunities that could reasonably affect a company's cash flows, access to finance, or cost of capital over the short, medium, and long term.
What IFRS S2 covers
Climate-specific disclosures: governance, strategy, risk management, and metrics and targets, including Scope 1, 2, and 3 greenhouse gas emissions. IFRS S2 effectively builds on and replaces the earlier TCFD (Task Force on Climate-related Financial Disclosures) recommendations.
Global adoption, as of 2026
As of early 2026, roughly 28 jurisdictions had adopted ISSB standards on a voluntary or mandatory basis, with a further dozen or so planning adoption. Adoption is genuinely global rather than concentrated in any one region:
- Adopted or mandatory: Hong Kong (mandatory for all HKEX-listed companies), Malaysia (baseline of its National Sustainability Reporting Framework), Singapore (climate disclosures under IFRS S2), Japan, Australia, Brazil (phased from FY2026), Nigeria, Kenya, Turkey, South Africa, New Zealand, South Korea, and others.
- In progress: the UK's Financial Conduct Authority has proposed aligning its climate disclosure rules with UK-adapted versions of the standards, mandatory for listed companies from January 2027 (currently voluntary).
- Not adopted directly: the United States has not adopted ISSB standards as such — its patchwork instead includes a now-withdrawn SEC climate disclosure rule and state-level requirements like California's SB 253 and SB 261, which reference similar underlying methodology (the GHG Protocol) without being ISSB-branded.
Why this matters for tagging
As ISSB adoption spreads, jurisdictions increasingly expect structured, machine-readable submission of IFRS S1/S2-aligned disclosures — the same underlying logic as ESRS XBRL, applied to a different (though related) standard. A company reporting in multiple ISSB-adopting jurisdictions may need consistent underlying data tagged slightly differently for each. See our ESRS vs ISSB comparison for how the two major frameworks relate.
Frequently Asked Questions
Is ISSB the same as ESRS?
No, though the two are designed to interoperate where possible — ESRS is the EU's own standard under CSRD, while ISSB is a global baseline. See our ESRS vs ISSB comparison for the detail.
Has the US adopted ISSB standards?
Not directly — the US has no federal ISSB adoption. The SEC's own climate disclosure rule was withdrawn after litigation, and state-level rules like California's SB 253/261 use similar underlying methodology without being formally ISSB-aligned.
Does every ISSB-adopting country require digital tagging?
Not universally — adoption of the disclosure standards themselves and adoption of a digital/XBRL tagging requirement for those disclosures are separate questions, and vary by jurisdiction. Confirm the specific requirement for your reporting jurisdiction.