ISSB publishes IFRS S1 and IFRS S2
ISSB
International Sustainability Standards Board (ISSB)
IFRS S1 and IFRS S2 are the ISSB's global disclosure standards for sustainability-related and climate-related financial risks. National regulators decide whether and when the standards become mandatory in each jurisdiction.
Next relevant deadline
Japan has the next confirmed mandatory ISSB-aligned deadline. Companies listed on the Tokyo Stock Exchange Prime Market with an average market capitalization of 3 trillion yen or more must include IFRS S1 and IFRS S2 aligned disclosures in their annual securities report for the fiscal year ending March 31, 2027.
A second deadline follows in the UK. The Financial Conduct Authority has proposed mandatory climate disclosure for UK-listed companies for reporting periods beginning January 1, 2027, with final rules expected in autumn 2026.
Keydates and Milestones
What the regulation requires
The IFRS Foundation created the ISSB in 2021 to consolidate a fragmented landscape of voluntary sustainability frameworks. Through a series of mergers, the ISSB now maintains the Task Force on Climate-related Financial Disclosures' recommendations, the Sustainability Accounting Standards Board (SASB) Standards, and the Integrated Reporting Framework.
IFRS S1 and IFRS S2 cover risks that could affect a company's own cash flow, financing, or cost of capital.
The ISSB has no enforcement power of its own, so reporting only becomes mandatory once a national regulator adopts, endorses, or otherwise incorporates the standards into local law. That adoption mechanism is also why effective dates, scope, and phasing differ by jurisdiction, even though the disclosure content itself stays the same.
Common ISSB implementation challenges
Effective dates and scope thresholds differ by jurisdiction
Japan phases in mandatory SSBJ reporting by market capitalization tier. The UK is proposing a listed-company scope tied to existing Listing Rule categories, while Hong Kong, and Australia each apply separate thresholds and timelines of their own. A company operating across several of these markets tracks several separate compliance clocks rather than one.
Existing sustainability data is not organized for IFRS S2 disclosure
Companies already reporting under the EU's Corporate Sustainability Reporting Directive (CSRD) collect data on their own climate risk and on their impact on the environment and people. IFRS S2 only needs the climate risk portion, and pulling that subset out without re-running the full data collection is a mapping problem most companies have not solved.
Scope 3 emissions data at supplier level is incomplete or unverifiable
IFRS S2 requires full value chain emissions disclosure, including financed emissions for financial institutions. Most companies collect Scope 3 estimates from spend-based proxies rather than supplier-level activity data, which limits both accuracy and audit readiness.
Assurance requirements apply before most companies file a first disclosure
In Australia, limited assurance applies from a company's very first reporting year. In Japan, an outside auditor formally reviews a company's disclosure the year after it becomes mandatory. In the UK, assurance is not required by law, but the standard takes effect before most companies file their first disclosure, putting a company under the same immediate pressure from investors rather than regulators.
Map supplier, emissions, and disclosure data into ISSB-aligned reporting
The osapiens HUB the supplier data already collected for risk management and due diligence into the financial materiality inputs that IFRS S1 and IFRS S2 disclosures require, without the need for a second data collection exercise.
Trace Scope 3 emissions to the supplier record
Supplier-level activity data, collected once through the supplier portal, feeds Scope 3 emissions calculations by category instead of spend-based estimates, and stays linked to the same supplier profile used for risk screening.
Map existing CSRD data directly into IFRS S1 and IFRS S2 disclosures
Companies already reporting under the EU's Corporate Sustainability Reporting Directive (CSRD) collect both financial materiality and impact materiality data. The Reporting Cockpit and Disclosure Management modules extract the financial materiality portion and map it directly into IFRS S1, IFRS S2, VSME, and GRI templates.
Extend the same due diligence data layer to CSDDD
The supplier profile that generates climate risk data for ISSB-aligned disclosure is the same profile used for due diligence obligations under the EU's Corporate Sustainability Due Diligence Directive (CSDDD). Supplier risk, emissions, and due diligence findings are collected once and reused across both obligations.
ADDITIONAL RESOURCES
Error 429 Too many requests
Too many requests
Error 54113
Details: cache-cmh1290094-CMH 1788879821 3508888180
Varnish cache server
Error 429 Too many requests
Too many requests
Error 54113
Details: cache-cmh1290094-CMH 1788879821 3508888180
Varnish cache server
Error 429 Too many requests
Too many requests
Error 54113
Details: cache-cmh1290094-CMH 1788879821 3508888180
Varnish cache server
Error 429 Too many requests
Too many requests
Error 54113
Details: cache-cmh1290094-CMH 1788879821 3508888180
Varnish cache server
Error 429 Too many requests
Too many requests
Error 54113
Details: cache-cmh1290094-CMH 1788879821 3508888180
Varnish cache server
Error 429 Too many requests
Too many requests
Error 54113
Details: cache-cmh1290094-CMH 1788879821 3508888180
Varnish cache server