Thai ESG Listed Disclosure: SET Framework and Investor Pressure

Questions this report answers

What's mandatory ESG disclosure for SET-listed companies? Per PIM Legal: ESG-related disclosures are mandatorily required and must comply with the Thai SEC's reporting guidelines, primarily through Form 56-1 One Report annually. The disclosure covers climate change, environmental preservation, low-carbon footprint, and inequality reduction. The framework is comply-or-explain — if a company doesn't disclose, e.g., its GHG emissions, it must explain why. 2025 saw stricter requirements on environmental impact, governance practices, and social policies per Slaughter and May.^{[2, 3, 1]}

What's the ISSB Roadmap and when does Thailand adopt IFRS S1 / S2? Per Slaughter and May: the Thai SEC proposed adoption of IFRS S1 (general sustainability) and IFRS S2 (climate) as part of its ESG disclosure reform initiative — the 'ISSB Roadmap'. Public consultation concluded 19 December 2024; the Q3 2025 draft-hearing step was the next procedural milestone, with formal adoption still the item to track. The structural implication is alignment with global investor expectations and ASEAN-peer regulatory regimes (Singapore SGX, Bursa Malaysia) per Reccessary.^{[3, 9]}

What benchmarks measure Thai-listed-company ESG-disclosure quality? Per the World Bank's ESG Disclosure Assessment of Thailand's Listed Companies: external-benchmark methodology evaluates governance, climate, social, and risk-management disclosure quality. Per SET: the SETESG-rated index identifies exemplar disclosure-quality companies; SETHD high-dividend index is the dividend-tier counterpart. Per Asian Legal Business: Thailand's ESG-progress narrative shows steady disclosure-quality improvement since 56-1 One Report mandate. Per Chambers: ESG due-diligence is standard for M&A and PE transactions.^{[5, 7, 4, 10]}

How does foreign-investor pressure on SET-listed names work? Per Reccessary ASEAN coverage and Deloitte SEA analysis: ESG-rating providers (MSCI, Sustainalytics, Refinitiv) build ratings used by foreign institutional investors for portfolio-construction decisions; investors with ESG mandates exclude or underweight low-rated names. Active-engagement campaigns target governance and climate-disclosure improvements; credible disclosure quality is increasingly material to foreign-investor inflows. Big 4 audit firms (KPMG, PwC, Deloitte, EY) provide assurance services to support disclosure credibility.^{[9, 8]}

Executive summary

Thai SET-listed-company ESG disclosure is mandatory under the SEC's Form 56-1 One Report framework with comply-or-explain regime per PIM Legal. The disclosure covers governance, climate change, environmental preservation, low-carbon footprint, and inequality reduction. 2025 saw stricter requirements on environmental impact, governance practices, and social policies per Slaughter and May. Thailand is in the middle of a structural ESG-disclosure-regime upgrade: the SEC's ISSB Roadmap proposed adoption of IFRS S1 and IFRS S2; public consultation closed 19 December 2024; Q3 2025 hearing on draft implementing regulations; formal adoption to follow.^{[2, 3]}

SET supports the disclosure infrastructure with the SETESG-rated index (exemplar disclosure-quality names) and SETHD high-dividend index, plus the annual SET sustainability development report. The World Bank's ESG Disclosure Assessment of Thailand's Listed Companies provides external-benchmark methodology. Big 4 audit firms (KPMG, PwC, Deloitte, EY) provide assurance services that support disclosure credibility. The Asian Legal Business 'ESG journey' framing reflects steady disclosure-quality improvement since the 56-1 mandate.^{[7, 5, 4, 8]}

Foreign-investor pressure on SET-listed names is rising. ESG-rating providers (MSCI, Sustainalytics, Refinitiv) build coverage; investors with ESG mandates exclude or underweight low-rated Thai names. Per Reccessary ASEAN coverage: credible disclosure is increasingly material to foreign-investor inflows. The 2026 outlook is continued disclosure-quality maturation, IFRS S1 / S2 formal adoption, and growing active-engagement campaigns. For Thai-listed companies, ESG-disclosure investment is now table stakes rather than optional — the question is competitive disclosure quality, not whether to disclose.^{[9, 10]}

ESG disclosure framework and ISSB roadmap milestones