For nearly a decade, the SET ESG Ratings were the benchmark of corporate sustainability for companies listed on the Stock Exchange of Thailand. From 2026 they are being retired and replaced by FTSE Russell ESG Scores. This guide explains what the SET ESG Ratings measured, how they were assessed, the latest results, and what the shift to a global rating model means for every listed Thai company.
What are the SET ESG Ratings?
The SET ESG Ratings (formerly the Thailand Sustainability Investment, or THSI, list) were an annual assessment run by the Stock Exchange of Thailand to recognise listed companies with strong environmental, social and governance practices. A company that qualified could use the rating in investor communications, and the ratings fed Thailand’s sustainable-investment indices and the growing pool of ESG funds.
How were the SET ESG Ratings assessed?
Assessment was questionnaire-based. Companies completed a detailed sustainability questionnaire, and the SET scored responses across the environmental, social and governance dimensions, with corporate-governance and risk screening applied on top. Qualifying companies received a tiered rating (from AAA down to C). Because the process relied on what companies reported in the questionnaire, preparation and internal data quality largely determined the outcome.
SET ESG Ratings 2025 results
In the 2025 assessment, 265 listed companies qualified for a SET ESG Rating — up from 219 the year before — with higher average scores across all three ESG dimensions. The SET framed the improvement as evidence that Thai issuers were ready for the transition to a global benchmarking model.
Why SET is replacing the ratings with FTSE Russell ESG Scores (2026)
From 2026 the SET will publicly announce FTSE Russell ESG Scores and discontinue the SET ESG Ratings. The change is fundamental, not cosmetic. Where the old ratings were built from a private questionnaire, FTSE Russell scores are derived only from publicly disclosed information — your annual report, your sustainability report and your corporate website. FTSE Russell applies a three-tier structure of 3 pillars, 14 themes and over 300 indicators, with Thai companies assessed on roughly 125 indicators on average. We cover the mechanics in detail in our guide to the SET’s move to FTSE Russell ESG Scores in 2026.
What changes for listed companies
The single biggest shift is this: you can no longer “manage” your score through a questionnaire. If a data point is not published — clearly, and in English — it does not count. Three consequences follow for every SET- and mai-listed issuer:
- English disclosure now drives the score. FTSE Russell assesses public information; thin or Thai-only disclosure leaves indicators unscored.
- Your annual report and 56-1 One Report become rating documents. The ESG content inside them is read directly by the rater, so quality and completeness matter more than ever.
- Materiality must be defensible. A robust double materiality assessment determines which topics you disclose against — and therefore which indicators you can score on.
English drives the score
FTSE Russell assesses public information. Thin or Thai-only disclosure leaves indicators unscored.
Reports become rating documents
The ESG content in your annual report and 56-1 One Report is read directly by the rater.
Materiality must be defensible
A robust double materiality assessment decides which topics — and indicators — you can score on.
How to prepare for the FTSE Russell transition
- Map the FTSE Russell indicators against your current public disclosure and find the gaps.
- Run or refresh a double materiality assessment so your disclosure covers the topics that matter.
- Strengthen the ESG section of your annual report and 56-1 One Report — and publish it in high-quality English, not a rushed translation.
- Ensure every material data point appears in a publicly accessible place: the report, the sustainability report, or the corporate website.
- Treat English-language disclosure as a scored asset, with the same rigour as your financial statements.
Frequently asked questions
Are the SET ESG Ratings still valid in 2026? The SET is moving to publicly announcing FTSE Russell ESG Scores from 2026 and discontinuing the SET ESG Ratings. Companies should plan around the FTSE Russell methodology going forward.
Do I need an English sustainability report to score well? In practice, yes. FTSE Russell scores public disclosure, and English is the working language of global ratings and investors. Information disclosed only in Thai is at risk of going unscored.
Where does translation fit in? Your FTSE Russell score is calculated from the public, English-language documents you publish. Disclosure-grade bilingual translation of the annual report, 56-1 One Report and sustainability report is therefore part of the score itself — not an afterthought.
Turn disclosure into a higher score
Othello International combines ESG advisory with disclosure-grade bilingual translation built specifically for SET-listed companies — the only combination that addresses both what you disclose and how clearly it reads to a global rater. To benchmark your readiness for the FTSE Russell transition, talk to our team.
Related ESG guides
- Scope 1, 2 & 3 GHG Inventory for Thai Companies (TGO-Aligned)
- Double Materiality Assessment, Explained for Thai Issuers
- SET Moves to FTSE Russell ESG Scores in 2026: What SET-Listed Boards Must Do
- GRI vs SASB vs IFRS S1/S2: ESG Reporting Frameworks Explained (2026)
- 56-1 One Report Deadline 2026: Thailand Filing Dates & Bilingual Requirements