GRI, SASB and IFRS S1/S2 are the three ESG reporting frameworks Thai sustainability teams run into most often — and they are constantly confused for one another. The short version: they answer different questions for different audiences, and increasingly they are designed to work together rather than compete.
The quick map
- GRI — reports your company’s impact on the world (the economy, environment and people), for all stakeholders. This is “impact materiality”.
- SASB — reports the sustainability issues that are financially material to your industry, for investors. SASB Standards are now maintained by the ISSB and underpin IFRS S1.
- IFRS S1 & S2 — the ISSB’s global baseline for sustainability-related financial disclosure (S1 general, S2 climate), again for investors.
GRI: impact materiality
กระบวนการรับรองนิติกรณ์เอกสารของ GRI Standards ask how your operations affect the outside world — emissions, water, labour practices, communities. The audience is broad: regulators, employees, communities and investors. GRI is the most widely used framework globally and is well established among Thai listed companies for the sustainability narrative in the 56-1 One Report.
SASB: financial materiality, by industry
SASB takes the opposite lens: which sustainability issues are likely to affect enterprise value in your specific industry. Because it is industry-specific and investor-focused, SASB became the practical backbone for investor-grade ESG data — and the ISSB now maintains the SASB Standards and references them inside IFRS S1.
IFRS S1 and S2: the ISSB global baseline
IFRS S1 and S2 are the ISSB’s standards for sustainability-related financial disclosure. S1 covers governance, strategy, risk management and metrics across all material sustainability topics; S2 is a deeper, TCFD-aligned climate standard. Both use financial materiality — what could reasonably affect the company’s prospects and value.
How they fit together (double materiality)
GRI’s outward, impact view and the ISSB’s inward, financial view are two halves of “double materiality”. Used together they cover both how the world affects your business and how your business affects the world. GRI and the IFRS Foundation have issued joint guidance on using the GRI and ISSB Standards together, so reporting against one no longer means starting from scratch for the other.
What this means for SET-listed Thai companies
Thailand is phasing in IFRS S1/S2, beginning with SET50 companies from 2026 and SET100 from 2027, while the SET moves to FTSE Russell ESG Scores in 2026 — an assessment built on publicly disclosed, largely English-language information. In practice most SET-listed companies will keep a GRI-based sustainability narrative and layer ISSB (IFRS S1/S2) financial-materiality disclosures on top — and both need an accurate English version in the annual report / 56-1 One Report.
Which framework should you use?
It is rarely either/or. A typical Thai listed company reports its impacts with GRI, addresses investor-grade financial materiality with IFRS S1/S2 (with SASB as the industry lens), and ensures every disclosure exists cleanly in both Thai and English. The goal is one coherent, bilingual sustainability story — not three disconnected reports.
Frequently asked questions
Is GRI being replaced by IFRS S1/S2?
No. GRI (impact materiality) and IFRS S1/S2 (financial materiality) serve different audiences and are designed to be used together.
What happened to SASB?
SASB Standards are now maintained by the ISSB and are referenced within IFRS S1 as industry-specific guidance.
Do Thai listed companies have to use IFRS S1/S2?
They are phasing in — SET50 from 2026 and SET100 from 2027 — so affected companies should prepare disclosures (and English translations) ahead of their year.
Related ESG guides
- 56-1 One Report Deadline 2026: Thailand Filing Dates & Bilingual Requirements
- Carbon Credits in Thailand 2026: T-VER, Premium T-VER and What Corporates Need to Know
- What Is ESG? A Practical Guide for Thai Companies (2026)
- CSRD After the Omnibus: What Thai Suppliers to EU Companies Actually Need to Provide (2026)
- CBAM in 2026: What Thai Exporters Must Do as the Definitive Phase Begins