![\"Thailand](\"https:\/\/i0.wp.com\/www.othellointernational.com\/wp-content\/uploads\/2026\/07\/thailand-mandatory-climate-disclosure-infographic.png?resize=800%2C2000&ssl=1\")
<\/figure>\n\n\n\nFrom “comply or explain” to mandatory<\/h2>\n
Thailand has run a “comply or explain” model, where disclosure gaps could be explained rather than closed. The SEC’s ISSB Roadmap changes that \u2014 transitioning to a mandatory disclosure regime aligned with the ISSB Standards, led by climate-related disclosure (IFRS S2)<\/strong>. Large-cap listed companies are first, from 2026, with the requirement expected to phase across the broader market thereafter. If you are a large SET-listed company, the practical question is no longer whether<\/em> to disclose climate data, but whether your disclosure will withstand assurance. See what SET-listed companies must disclose under IFRS S1 and S2<\/a>.<\/p>\n\n ESG disclosures are made annually in Form 56-1 One Report<\/strong>. The sustainability section of that filing is where your IFRS S1\/S2 climate content will sit \u2014 governance, strategy, risk management, and metrics and targets. Getting the structure right there is what turns raw sustainability data into a defensible regulatory disclosure. See how to approach the 56-1 One Report ESG section<\/a>.<\/p>\n\n To ease the transition, SET has launched the ESG Data Platform<\/strong> \u0e41\u0e25\u0e30 SET Carbon<\/strong> \u2014 tools that help listed businesses improve sustainability disclosure and track greenhouse-gas emissions, integrated to reduce duplication of work. They are a genuine help for data collection. But the outputs are inputs: emissions figures and platform data still need to be turned into a clear, audit-ready narrative disclosure. Start from a robust Scope 1, 2 & 3 GHG inventory<\/a> before you draft.<\/p>\n\n The move from voluntary to mandatory disclosure shifts the standard of care applied to every climate statement you publish. Under a voluntary regime, an incomplete or optimistic disclosure carried mainly reputational risk. Under a mandatory, assurance-oriented regime aligned with the ISSB Standards, the same disclosure becomes a regulated filing \u2014 one that must be internally consistent, supported by documented methodology, and defensible if challenged. In practical terms, three things change for the sustainability and IR functions.<\/p>\n IFRS S2 organises climate disclosure around the same four pillars familiar from the TCFD framework. Mapping your 56-1 One Report ESG section to these pillars from the outset makes the eventual assurance process far smoother.<\/p>\n Running in parallel, SET is upgrading its ESG Ratings by adopting the FTSE Russell ESG model<\/strong>, with full implementation expected in 2026. That means the same disclosure feeds two audiences at once: the mandatory regulatory filing \u0e41\u0e25\u0e30<\/em> your ESG rating. Weak or inconsistent disclosure now costs you twice. See what the SET move to FTSE Russell ESG scores<\/a> means for boards.<\/p>\n\n Here is the part most companies underestimate. Filings are prepared in Thai; FTSE Russell, MSCI, and global investors read your disclosure in \u0e2d\u0e31\u0e07\u0e01\u0e24\u0e29<\/strong>. When the Thai and English versions drift \u2014 a hedged commitment stated as firm, a metric defined differently, a boundary described inconsistently \u2014 you have a misstated disclosure<\/strong> and a weaker rating, from the same document. Under a mandatory regime, that is a compliance exposure, not a translation nicety. ISO 17100-certified bilingual disclosure, produced by specialists who understand IFRS S1\/S2 language, closes that gap.<\/p>\n The risk is subtle because it rarely comes from an obvious mistranslation. It comes from register and precision. A Thai phrase that reads as an aspiration can, translated carelessly, harden into a firm commitment the company never intended to make \u2014 or, conversely, a definite target can soften into vague intention, costing scored indicators. Emissions boundaries, base years, and the scope of a target are exactly the details where a small wording difference between the Thai and English versions creates a genuine discrepancy between two “official” versions of the same regulated filing. Reconciling the two languages against a single agreed meaning \u2014 rather than translating one after the other \u2014 is what prevents that drift.<\/p>\n\n When does mandatory climate disclosure start in Thailand?<\/strong> Under the SEC’s ISSB Roadmap, mandatory, ISSB-aligned climate disclosure is expected to begin with large-cap SET-listed companies from 2026, phasing across the broader market thereafter. Because transitional details are still being finalised, confirm your specific cohort and timing with the SEC and your auditors.<\/p>\n Is IFRS S1 also mandatory, or only IFRS S2?<\/strong> The roadmap is led by climate-related disclosure under IFRS S2, with IFRS S1’s general sustainability-disclosure requirements forming the surrounding framework. Both should be treated as the direction of travel for large issuers.<\/p>\n Do the Thai and English versions both need to be accurate?<\/strong> Yes. The Thai version is the regulatory filing; the English version is what global investors and rating providers read. Any drift between them is a disclosure and rating risk under a mandatory regime.<\/p>\n\n Othello International is an ISO 17100-certified bilingual ESG-disclosure and translation firm for SET-listed companies. We help boards close the IFRS S1\/S2 gap and produce disclosures that read correctly \u2014 and identically \u2014 in both languages. Explore our ESG disclosure advisory<\/a> \u0e2b\u0e23\u0e37\u0e2d talk to our team<\/a>.<\/p>\n\n\n\n \ud83d\udcd8 Free resource:<\/strong> Explore The FTSE 2026 Playbook Library<\/a> \u2014 Othello’s ESG disclosure playbook plus focused editions for Thai banks, energy, property, healthcare, technology and more.<\/p>\n\n\n Othello International is a Bangkok-based bilingual (EN\u2194TH) technical translation and ESG advisory firm. Related specialist services:<\/p>\n\n\n\nWhere it lands: the 56-1 One Report<\/h2>\n
New SET tools: ESG Data Platform & SET Carbon<\/h2>\n
What “mandatory” actually changes in practice<\/h2>\n
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The four IFRS S2 pillars, applied to a Thai filing<\/h2>\n
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The FTSE Russell overlay<\/h2>\n
Why bilingual accuracy is now a compliance issue<\/h2>\n
What to do in the second half of 2026<\/h2>\n
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Frequently asked questions<\/h2>\n
Prepare your mandatory climate disclosure with the right partner<\/h2>\n
Related services from Othello International<\/h2>\n\n\n\n