“Double materiality” is one of the most misunderstood ideas in sustainability reporting — and one of the most important for SET-listed companies preparing for IFRS S1/S2 and the 2026 FTSE Russell transition. In plain terms, it means looking at sustainability through two lenses at once: how the world affects your business, and how your business affects the world.
The two lenses of materiality
A double materiality assessment identifies which sustainability topics matter enough to report, judged on two criteria:
- Financial materiality (outside-in): how environmental and social issues could affect your company’s value, cash flows, and access to capital. This is the lens used by investors and by the IFRS S1 and S2 standards.
- Impact materiality (inside-out): how your operations affect the economy, environment, and people — regardless of financial consequence. This is the lens used by the GRI Standards and the EU’s CSRD.
A topic is “material” if it is significant under either lens. We unpack how these frameworks fit together in our guide to GRI vs SASB vs IFRS S1/S2.
Why Thai issuers need it now
Three forces make double materiality practical, not theoretical, for SET-listed companies: the phased adoption of IFRS S1/S2 (financial materiality), the move to FTSE Russell ESG Scores in 2026 (which reward complete, structured disclosure), and the EU CSRD reaching Thai companies with significant EU operations or exports (which mandates double materiality outright). A single, well-run assessment satisfies all three.
How to run a double materiality assessment
- Map your topics against a recognised list (GRI, SASB/ISSB industry standards, sector ESG issues).
- Engage stakeholders — investors, employees, customers, communities, regulators — to test what matters.
- Score each topic on financial materiality and impact materiality separately.
- Validate with the board and document the methodology, so it is auditable and disclosable.
- Disclose the result — a materiality matrix and narrative — in your One Report and sustainability report.
Getting it reported — in both languages
A materiality assessment only earns recognition once it is published clearly, and for SET-listed companies that means Thai and English. Othello International combines double materiality assessment with ISO 17100-certified bilingual translation, so your methodology, matrix and narrative are consistent and investor-ready in both languages. Talk to our ESG advisory team to scope an assessment.
Related ESG guides
- 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
- 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)