Double materiality means assessing sustainability topics from two perspectives simultaneously: impact materiality (inside-out) — how the company affects people and planet — and financial materiality (outside-in) — how sustainability topics affect the company’s financial position. A topic is material if either threshold is met. A topic is highly material if both are met.

It matters because (1) GRI 3 (2021) and ESRS require it; (2) FTSE Russell methodology assesses indicators that span both perspectives; (3) institutional investors increasingly demand double-materiality disclosure as a signal of methodology rigour; (4) the conventional “single materiality” approach (financial only — older SASB and pre-IFRS S2 thinking) is increasingly seen as incomplete. For Thai SET-listed companies, double materiality is the methodologically defensible standard for 2026 onwards.

Both frameworks require double materiality but emphasise it differently. GRI 3: Material Topics 2021 is structured around impact materiality as the primary lens, with financial materiality as a complementary consideration — the GRI tradition is centred on the impact-on-stakeholders perspective. ESRS 1 (General Requirements) + EFRAG Implementation Guidance 1 (IG 1) is structured as fully balanced double materiality — both axes carry equal methodological weight, with detailed thresholds and scoring guidance published.

In practice, Othello’s methodology runs both axes in parallel and produces deliverables that satisfy both standards simultaneously. The cross-reference table in the topic register shows which GRI 3 reference, which ESRS topical standard, and which IFRS S1 disclosure each material topic maps to. The methodology document discloses how thresholds were set against each standard’s guidance.

The Thai SEC mandate under Tor Chor 55/2563 does not yet explicitly require double materiality methodology, but SEC guidance increasingly references it. The practical drivers are: (1) FTSE Russell methodology — the 2026 SET ESG standard — assesses indicators that span both axes, so a double-materiality register produces FTSE-aligned scoping by construction; (2) GRI 2021 reporting — most SET-listed companies use GRI as their reporting framework, and GRI 3 requires impact materiality; (3) IFRS S1/S2 — becoming Thai SEC mandate in 2026 — requires financial materiality.

So while no single mandate forces double materiality on Thai issuers today, the combination of FTSE + GRI + IFRS effectively requires it. Companies running single-axis materiality methodology produce a register that’s incomplete for at least one of these frameworks. For SET-listed companies with EU institutional shareholders (common among SET50), ESRS-aligned double materiality is increasingly an investor expectation.

Impact materiality assessment runs each candidate topic through a structured scoring on four dimensions: severity (how bad is the impact when it occurs), scope (how many people or how large an ecosystem affected), irremediability (can the impact be reversed), and likelihood (how probable). Each dimension scored on a calibrated scale (typically 1–5), with sector-specific benchmarks for what constitutes severe vs moderate.

Scoring inputs draw from: GRI 3 sector standards (where applicable — Oil & Gas, Coal, Agriculture), ESRS topical standards (E1 Climate, E2 Pollution, E3 Water, E4 Biodiversity, E5 Resource Use, S1–S4 Social, G1 Governance), peer benchmarking, stakeholder input from the AA1000SES engagement programme, and expert review by the in-house GRI 2021 Certified Trainer. Value chain extension is applied where the topic warrants (e.g., supply chain human rights for consumer goods, downstream emissions for energy).

Financial materiality assessment runs each candidate topic through a structured scoring on three dimensions: financial magnitude (what’s the reasonably likely effect on cash flows, access to capital, cost of capital, enterprise value), likelihood (how probable in the assessment period), and timeframe (short — within fiscal year; medium — 1–5 years; long — 5+ years). Each dimension scored against IFRS S1 materiality criteria.

Scoring inputs draw from: IFRS S1 General Requirements and IFRS S2 Climate-related disclosures, SASB Materiality Map for the company’s SICS industry, TCFD-aligned climate risk categories (physical, transition, liability), the company’s enterprise risk register where available, sector-specific risk benchmarks, and the in-house IFRS Foundation-certified specialist’s review. Cross-checked with the CFO office and risk management function. Output: financial-materiality scoring matrix aligned to IFRS S1.

Standard practice — endorsed by GRI 3 implementation guidance and ESRS — is a full refresh every 2–3 years, with an annual touch-point validation in between. The 2–3 year cycle reflects that material topics tend to be stable across short periods; what changes more rapidly is the threshold (an issue becomes more or less severe), the framework standards (new ESRS topical standards), or the stakeholder universe (new shareholders, regulators, customer segments).

Earlier refresh is warranted when: (1) major strategy or sector pivot — entering new business segments materially shifts material topics; (2) M&A integration — combined-entity materiality is rarely a simple merge of two registers; (3) new framework standards — ESRS topical standards roll-out is currently driving early refresh; (4) significant external event — major regulatory shift, climate event, or stakeholder-pressure campaign on a previously non-material topic. The 3-year cycle engagement structure accommodates the standard cadence with cost efficiency.

The steering committee typically includes: Chief Sustainability Officer or Head of Sustainability (chair); IR / Investor Relations (financial-materiality input); CFO or CFO designate (financial impact validation); Corporate Secretary / CG (governance topic validation); HR / People function (social topic input); Operations / EHS (operational impact validation); Risk Management (financial risk overlay). Optional but recommended additions: legal counsel (regulatory topic input), procurement (supply chain materiality), customer-facing function (customer-stakeholder input).

For board endorsement, the assessment is typically reported to the board sustainability committee or risk committee for review and endorsement, then to the full board for formal adoption. Some SET-listed companies use a two-stage endorsement: management steering committee approves the methodology and matrix, board sustainability committee adopts the register, full board endorses for disclosure publication. Othello’s methodology document records the endorsement chain for audit-defensibility.

The double-materiality register is the architectural foundation of the entire disclosure cycle. Material topics become disclosure sections — each highly-material topic gets a dedicated section in 56-1 Part 1.3 (Sustainability Business Development) and in the standalone sustainability report. Topics material on one axis are disclosed with less depth. Topics not material are referenced but not full-section disclosed. The topic-to-disclosure mapping is delivered as part of the materiality output.

The materiality narrative — the written record of how the assessment was conducted — is drafted by Othello to slot directly into 56-1 Part 1.3.2 “Materiality and Stakeholders” and the corresponding section of the standalone sustainability report. Bilingual EN/TH drafted in lockstep. The cross-framework mapping table also drives the GRI Content Index, SASB Index, IFRS S2 climate section scope, and FTSE Russell indicator mapping. See 56-1 service → · Bilingual Reporting →

Yes. Othello responds to formal procurement processes for materiality assessment from SET-listed corporates, prospective listing applicants, EU-shareholder-influenced Thai issuers, and procurement teams scoping larger ESG advisory engagements. Standard procurement requirements are met: ISO 17100:2015 certification, ATA + ATC accreditation, GDPR + PDPA compliance, mutual NDA from first email, in-house credentialled methodology owners (GRI 2021 Trainer, IFRS Foundation, AA1000AS ACSAP, ISO 14064 Lead Auditor, TGO Auditor), bilingual stakeholder engagement capability, and SET-listed engagement references available under mutual NDA at procurement stage.

Standard RFP response is 3–5 วันทำการ for materiality methodology engagements. RFP response covers: methodology approach (GRI 3 + ESRS + IFRS S1 + SASB + AA1000SES alignment), tier recommendation per scenario, in-house bench credentials, stakeholder engagement programme structure, capacity allocation, pricing structure, engagement timeline, and sample matrix structure (anonymised). Quote response on engagement scoping is within one business hour of receipt of source files and signed NDA.