Thailand’s first mandatory climate disclosure is now close enough to plan around. On 28 November 2025 the SEC revised its sustainability-disclosure principles to align with the ISSB standards, naming IFRS S1 and IFRS S2 directly, climate-first, Scope 1 and Scope 2 to begin with. The cohort is fixed by the December 2026 SET50 index review — four months away — and those companies report for FY2027, filing in 2028.
There is a detail in that sentence that almost no Thai briefing has picked up, and it is not a technicality. IFRS S1 and IFRS S2 have never been published in Thai. Not by the IFRS Foundation, and not by Thailand’s own standard-setter. The rule that will govern SET50 climate reporting exists, in authoritative form, only in English.
That is a genuinely unusual position for a Thai reporting obligation, and it has consequences for how sustainability teams staff, draft and review the FY2027 report. Here is what is actually true, sourced to primary documents — and what it means in practice.
The standard has never been published in Thai
In March 2025 the IFRS Foundation announced new translations of the IFRS Sustainability Disclosure Standards and their supporting materials. The list is specific: Arabic, Brazilian Portuguese, Simplified Chinese, French, Japanese, Korean, Mongolian, Romanian and Spanish. Thai is not on it, and Thai does not appear in the translation filter on the Foundation’s Sustainability Standards Navigator either.
Nor has the gap been filled domestically. The Federation of Accounting Professions (TFAC) has published educational material introducing IFRS S1 and S2 in Thai — but as at August 2026 its standards library carries no sustainability-reporting family at all. Its four standard families cover financial reporting, auditing, education and ethics. Draft papers have circulated, but nothing has been issued: no Thai standard number, no effective date, no authoritative Thai text in force. Thailand’s route is adoption by reference to the English standards — in full, with no jurisdictional modification and no carve-outs — rather than enactment of a Thai equivalent.
The translation is not simply forgotten, either — it is a known blocker. The SEC’s own strategic-plan performance report identifies the licence agreement between TFAC and the IFRS Foundation, permitting translation and publication of the standards, as a critical precondition for issuing its related notifications and forms. Which is worth sitting with: the reason the final rule has not landed is, in part, a translation right. And as at August 2026 that final SEC notification has still not been issued — the 28 November 2025 announcement set the principles and the ladder, and the implementing notification remains in progress.
This is worth stating plainly because the alternative assumption is so natural. Thai finance teams have three decades of experience with a standard-setter that hands them a Thai text. For sustainability, that text does not exist.
Accounting got a Thai text. Sustainability did not.
The contrast with the accounting side is stark, and it is the IFRS Foundation itself that draws it. Its jurisdiction profile for Thailand states the position in one line:
IFRS Accounting Standards in English are not directly adopted in Thailand because the official language in Thailand is Thai.
IFRS Foundation · Thailand jurisdiction profileThe reason is legal, not stylistic: accounting standards enforced as law must be in Thai under the Accounting Professions Act B.E. 2547 (2004). So TFAC’s Thai Accounting Standard Setting Committee translates each IFRS Accounting Standard into Thai, and the resulting TFRS takes effect with a deliberate one-year delay behind the international standard. That machinery has worked for years — and that same jurisdiction profile is explicit that it covers IFRS Accounting Standards only. The sustainability standards sit outside it.
Note the asymmetry, because it shows this is not simple neglect. On the assurance side, Thailand did issue a Thai-language standard: TFAC released TSSA 5000, its general sustainability assurance standard, on 9 April 2026, revoking TSAE 3410. So the verifier who signs off your GHG numbers works to a Thai standard, while the report they are verifying is prepared against an English one. That split runs right through the FY2027 filing →
| IFRS Accounting Standards | IFRS S1 & S2 in Thailand | |
|---|---|---|
| Authoritative Thai text | Yes — TFRS, translated by TFAC | None published |
| Legal route | Enforced as law in Thai | SEC notification referencing the English standards |
| Effective-date lag | One year behind IFRS | No lag — SET50 reports FY2027 |
| Official translator | TASC, under TFAC | TFAC intended — licence still pending |
‘TSRS’ does not mean what most Thai briefings say
One more piece of housekeeping, and it matters more than it sounds. A great deal of Thai market commentary — and a fair amount of consultancy material — refers to the incoming rules as “TSRS 1” and “TSRS 2”. That label is wrong twice over, and using it in a board paper is an easy way to lose a room that knows the standards.
In TFAC usage TSRS means มาตรฐานงานบริการเกี่ยวเนื่อง — Thai Standard on Related Services. TSRS 4400 covers agreed-upon procedures; TSRS 4410, compilation engagements.
No SEC or TFAC primary document calls the incoming sustainability rules “TSRS 1” or “TSRS 2”. There is no such Thai standard to name.
TSRS 1 and TSRS 2 are Türkiye’s sustainability reporting standards. They have been misattributed to Thailand and the error has propagated.
Write “IFRS S1 and IFRS S2”, or “the SEC’s ISSB adoption.” Both are precise, both are defensible to a regulator or an auditor.
Three languages, one disclosure
Put the pieces together and a SET50 sustainability team is now working across three languages at once — and the handoffs between them are where disclosure quality leaks away.
Be precise about that last step, because the sloppy version of this argument is easy to rebut. FTSE Russell does not require English disclosure, and it has never said it disregards other languages — its FAQ says provision is made for other languages and then lists six “key” ones. Thai is not among the six. That is not a rule against you; it is a risk to manage. A theme documented thoroughly in your Thai One Report but thin, drifting or loosely rendered in the English edition is a theme an analyst may simply not credit — and under FTSE’s model, roughly 125 indicators are applied per company, exposure-weighted, on a 0–5 theme scale. The English edition is what gets read →
The middle step is where the untranslated standard bites hardest. Every requirement in IFRS S2 — “climate resilience”, “transition risk”, the metrics and targets language — has to be understood in English, applied to Thai operations, drafted in Thai for the SEC, and then rendered back into English for the raters. Without an authoritative Thai text, there is no official anchor for that terminology. Whatever your team settles on becomes the anchor. This is exactly where disclosure risk is created →
What to do before the December 2026 index review
The SET50 cohort becomes knowable at the December 2026 index review, and FY2027 drafting starts long before the filing. Four things are worth doing while there is still room to do them properly.
- Retire “TSRS 1 / TSRS 2” from your internal and external material. Use IFRS S1 and IFRS S2, or “the SEC’s ISSB adoption”.
- Build a bilingual terminology glossary for the S1/S2 vocabulary and lock it before FY2027 drafting — with no official Thai text, your glossary is the de facto standard.
- Reconcile the two editions clause by clause so the version the SEC reads and the version FTSE Russell scores say the same thing.
- Treat the English edition as a score-earning asset: ISO 17100 Translate–Edit–Proofread, terminology-locked, reviewed by someone who knows the standard, not just the language.
- Confirm your cohort at the December 2026 SET50 index review — and remember assurance carries no transition relief, even where reporting does.
See what your English edition is actually scoring
FTSE Russell scores SET-listed companies from public disclosure — no questionnaire. Run the free Gap Audit and see, theme by theme, where your English edition is leaving points on the table.
Run the free Gap AuditNone of this is an argument that Thailand has done something wrong. Adopting IFRS S1 and S2 by reference is fast, and it avoids the one-year translation lag that TFRS carries. But it moves a burden that used to sit with the standard-setter onto the companies — and onto whoever writes their disclosure. For the FY2027 cohort, the standard, the filing and the score are in different languages, and nobody official is going to reconcile them for you. Start with a clause-mapped bilingual One Report →, or review your IFRS S1 & S2 readiness →. Our ESG regulatory tracker keeps the dates current, and our ISO 17100 technical translation practice is where the English edition gets built.
Sources: IFRS Foundation — “New IFRS Sustainability translations available” (25 March 2025) and Thailand jurisdiction profile; TFAC standards library and TSRS 4400; TFAC Notification 13/2569 (TSSA 5000, 9 April 2026); SEC Thailand news release 298/2025 (28 November 2025) and the SET Thailand ISSB adoption roadmap; FTSE Russell ESG Scores and Indices FAQ v1.5 (December 2025) and ESG Data Model Methodology v1.2 (June 2026).
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