The Thai ESG Regulatory Tracker
One maintained, bilingual map of the rules reshaping disclosure for SET & mai-listed companies — the SET ESG → FTSE Russell transition, TSRS/ISSB phase-in, แบบ 56-1 One Reportและ EU CBAM. What it is, who it hits, when it lands, and what to do now.
the benchmark
in 2025
relief
disclosure
- 01SET ESG Ratings retired for FTSE Russell scores
- 02FTSE scores off your public English disclosure
- 03TSRS/ISSB climate disclosure phasing in
- 04CBAM definitive regime hits Thai exporters
Five regimes, one table.
Everything a Thai listed company’s disclosure team is tracking right now — with status pills instead of false precision where phase-in timing is still settling.
| Regime | What it is | Who it hits | Key dates / phase-in | Status | What to do now |
|---|---|---|---|---|---|
| SET ESG → FTSE Russellการเปลี่ยนผ่านสู่ FTSE Russell | SET is retiring its own SET ESG Ratings and adopting FTSE Russell ESG Scores as the domestic benchmark. LSEG & SET also launched the FTSE4Good Thailand Index. | All SET & mai issuers assessed for ESG standing (265 firms qualified in 2025, ~70% of combined market cap). | Pilot ran 2024–2025 (scores undisclosed). FTSE methodology becomes the reference from 2026. | Active 2026 | FTSE scores off public English disclosure. Get your English reporting FTSE-legible — not just translated. |
| TSRS / ISSB (IFRS S1–S2)มาตรฐาน TSRS ตาม ISSB | Thailand Sustainability Reporting Standards align to ISSB IFRS S1 (general) & S2 (climate). Mandatory, phased sustainability & climate disclosure for listed companies. | Phased by size: large-cap first, stepping down to all listed, mai, new mai IPOs, REITs, Infrastructure Trusts & Property/Infra Funds. | Phase-in indicatively ~2026–2027 for large-cap, extending through ~2029–2031 for smaller issuers & funds. | Phasing in | Use the transitional relief: climate-only (IFRS S2) is permitted for the first 5 years. Start with a clean GHG inventory. |
| แบบ 56-1 One Reportแบบ 56-1 One Report | The merged annual filing (old 56-1 + 56-2). ESG/sustainability disclosure sits on a comply-or-explain basis within a fixed clause architecture. | Every SET & mai-listed company, filed to the SEC in Thai. | Annual — due within the statutory window after fiscal year-end. | In force | English investor copy must map clause-by-clause to the Thai SEC filing — no drift between the two versions. |
| CBAM (EU border carbon)มาตรการ CBAM ของสหภาพยุโรป | The EU Carbon Border Adjustment Mechanism prices embedded carbon in imports. The definitive regime (with financial obligations) succeeds the 2023–2025 transitional phase. | Thai exporters in steel, aluminium, cement, fertiliser, hydrogen & downstream goods. | Transitional reporting 2023–2025; definitive regime from 2026 (certificate obligations). | Definitive 2026 | Build TGO-aligned Scope 1 & 2 (and product-level) GHG accounting now; line up independent verification. |
| TCFD → within ISSBกรอบ TCFD ภายใต้ ISSB | TCFD’s four pillars (governance, strategy, risk, metrics & targets) are absorbed into IFRS S2. The disclosure logic persists even as the standalone framework retires. | Any issuer building climate disclosure — the S2 backbone. | TCFD monitoring wound down 2024; logic continues under IFRS S2. | Absorbed | Structure climate narrative on the four pillars so it maps straight into IFRS S2. |
Orientation map, not legal advice. Verify specifics against SEC Thailand, SET and the European Commission for your filing year. Othello maintains this page as rules finalise.
★ The flagship report · FreeThis table is Chapter 3 of The State of Thai Corporate Climate Disclosure 2026 — 10 chapters, sector scorecards, and our full TGO-registry analysis. Read it →Thailand’s disclosure timeline.
Indicative phase-in from the FTSE pilot to full sustainability disclosure. Dates step down by issuer size — the mid-cap and mai window is where most preparation gets left too late.
- ’252024–2025
FTSE pilot & consultation
SET runs the FTSE Russell scoring pilot (scores undisclosed); SEC finalises TSRS implementing rules after the public consultation.
- ’262026
FTSE becomes the benchmark · CBAM definitive
FTSE Russell methodology is the domestic ESG reference. EU CBAM definitive regime begins. Large-cap TSRS phase-in starts.
- ’272027
Large-cap climate disclosure
Large-cap SET issuers report under IFRS S2 (climate-first). English disclosure quality now directly shapes FTSE scores.
- ’29~2029
Mid-cap & mai step-in
Phase-in extends to smaller listed companies, new mai IPOs, REITs and infrastructure/property funds — the segment the Big 4 price out.
- ’31~2031
Full sustainability disclosure
The 5-year climate-only relief closes; issuers move to full IFRS S1 + S2 sustainability disclosure.
The tracker, explained.
Straight answers on the transition every SET disclosure team is navigating in 2026.
01Is the SET ESG Rating really being discontinued?+
Yes — SET is transitioning its domestic ESG assessment to FTSE Russell ESG Scores, with LSEG and SET also launching the FTSE4Good Thailand Index. A pilot ran through 2024–2025 with scores undisclosed, and the FTSE methodology becomes the working reference from 2026. Always confirm the exact status against SET and SEC notices for your reporting year.
02What is the “climate-only” transitional relief under TSRS?+
Thailand’s ISSB-aligned rollout permits eligible issuers to report climate disclosure (IFRS S2, plus relevant S1) for an initial period — reported as roughly the first five years — before full sustainability disclosure is required, along with year-one relief from comparative-period figures. It lets companies start with a defensible GHG inventory and climate narrative rather than everything at once.
03Why does the FTSE transition favour bilingual disclosure?+
FTSE Russell scores companies largely off their public English-language disclosure. Under the old SET rating, the Thai filing carried the weight; under FTSE, your English report is what gets read and scored. That structurally rewards companies whose English disclosure is accurate, complete and framework-legible — not merely translated. This is where clause-mapped bilingual disclosure becomes a scoring advantage.
04Does CBAM affect my company if we only sell within Thailand?+
Directly, only if you export covered goods (steel, aluminium, cement, fertiliser, hydrogen and certain downstream products) into the EU. Indirectly, CBAM is pushing GHG accounting and verification expectations down supply chains, so Thai suppliers to exporters increasingly need TGO-aligned Scope 1/2 data too.
05How current is this tracker?+
It reflects the Thai regulatory picture as of mid-2026 and is framed with status pills rather than hard dates where phase-in timing is still settling. Treat it as an orientation map, not legal advice — verify specifics against SEC Thailand, SET and the European Commission for your filing year. Othello updates it as rules finalise.
One short email when a rule moves.
This tracker, delivered. A deadline-and-rule-change alert for Thai disclosure teams — nothing else:
- TSRS / ISSB phase-in dates as they finalise
- 56-1 One Report filing windows & clause changes
- FTSE Russell assessment-cycle timing
- CBAM obligations touching Thai exporters
Turn the rules into a filed report.
We build the bilingual disclosure that reads correctly in Thai for the SEC and scores well in English for FTSE Russell — clause-mapped, terminology-locked, delivered under NDA.