Overview
ISSB IFRS S1 and IFRS S2 are the global sustainability disclosure standards issued by the International Sustainability Standards Board. IFRS S1 sets the general requirements for sustainability-related financial disclosures, while IFRS S2 covers climate-related disclosures in detail.
This guide is for companies that want the full ISSB standards, not just a transition path from TCFD. It is the right entry point if you are building a new sustainability disclosure system or expanding into broader ISSB reporting across jurisdictions.
What ISSB Is
ISSB is the IFRS Foundation’s sustainability standards board, created to deliver a global baseline for sustainability-related financial disclosure. IFRS S1 sets the general disclosure requirements and applies alongside IFRS S2, which focuses on climate-related risk, opportunity, governance, strategy, metrics, and targets.
Together, the two standards give companies a structured way to disclose sustainability information that is decision-useful for capital markets and investors.
Why ISSB Exists
ISSB exists to reduce fragmentation in sustainability reporting and create a globally comparable baseline. It solves the problem of different climate and sustainability disclosure regimes by giving companies one main reporting structure that can be adapted across jurisdictions.
Companies use ISSB when they want investor-grade sustainability reporting with a broad, market-recognized standard set rather than a jurisdiction-specific overlay alone.
Who Uses ISSB
ISSB standards are being adopted or referenced across a growing number of jurisdictions, with reporting pathways visible in the UK, Singapore, Hong Kong, Japan, Australia, Canada, and many others. In many markets, the standards are being phased in for listed companies, large entities, and financial institutions.
This makes ISSB especially relevant for multinational groups, capital-markets reporters, and any company that needs one disclosure model that can travel across borders.
Where ISSB Is Used
ISSB is a global framework with growing adoption around the world, including in Asia-Pacific, Europe, the Middle East, and the Americas. Jurisdictional profiles and readiness tools now track how the standards are being incorporated into national reporting regimes.
Within a company, ISSB is used in sustainability reporting, climate-risk governance, investor communications, capital allocation, and enterprise risk management.
When ISSB Applies
ISSB timing depends on the jurisdiction adopting it, and many markets phase in compliance by reporting period and entity type. In practice, companies must follow the local legal baseline in each market where they report, then align internal controls to the most demanding applicable standard.
For global groups, the practical challenge is less about whether to report and more about harmonizing the timing and scope of multiple local rollouts.
Unique Requirements
IFRS S1 requires a complete set of sustainability-related financial disclosures, while IFRS S2 adds climate-specific detail, including emissions, transition plans, financed emissions, and industry-based metrics where relevant. IFRS S2 is more detailed than TCFD and includes additional requirements beyond the four classic TCFD pillars.
This gives companies a broader and more exacting standard than legacy climate-only reporting, while keeping the disclosures structurally familiar.
TCFD Integration And Migration Path
TCFD is being integrated into ISSB: companies applying IFRS S1 and IFRS S2 meet the TCFD recommendations because those recommendations are fully incorporated into the ISSB Standards. The IFRS Foundation says TCFD remains a valid entry point for companies moving toward ISSB, but the long-term destination is ISSB reporting.
If you already report using TCFD, you can migrate by reusing the same governance, strategy, risk, and metrics structure, then layering in the additional detail required by IFRS S1 and IFRS S2.
Data Retention And Archives
Your sustainability reporting records should be retained for multiple years to support continuity, audit readiness, and comparison across reporting periods. The GAIQ™ platform preserves published reports and supporting records as accessible archives, and prior ISSB or TCFD data can be carried forward or imported into later cycles.
That means historical disclosures do not get stranded when you move from legacy TCFD reporting into a full ISSB workflow.
How The GAIQ™ AI-Driven Platform Makes ISSB ESG Reporting Simpler
GAIQ preloads the relevant ESG Standards Frameworks based on your DMA results, so your team starts with the correct ISSB scope already configured. It maps data to IFRS S1 and IFRS S2 requirements, helps track mandatory versus voluntary items, and reduces duplicated work across jurisdictions.
GAIQ also makes the active framework visible in the app header and D Data pages, so users always know which standards are selected, assigned, or both.
Next Steps For Your Team
Use ISSB if you want a full sustainability disclosure framework rather than only a TCFD transition path. If you are already on TCFD, reuse your existing structure and migrate toward IFRS S1 and IFRS S2 in stages, keeping legacy records available as archives in GAIQ.
Adopt AI technology to automate data collection, mapping, and reporting workflows, which can significantly reduce the time and effort required for ESG reporting.
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Executive Summary
ISSB IFRS S1 and IFRS S2 are the global baseline for sustainability related financial disclosures and climate-related disclosures. TCFD remains relevant as a migration path, but it is now embedded inside ISSB rather than separate from it.
For companies building a future-proof reporting stack, ISSB is the destination standard and TCFD is the stepping stone.