Why three standards?
GRI, SASB, and ISSB were not designed to compete — they were designed for different audiences with different needs. GRI was built for accountability to society. SASB was built for financial investors who needed comparable, industry-specific data. ISSB was built as a global investor-focused baseline that could become the foundation for mandatory disclosure regimes worldwide. Understanding the audience of each standard is the key to using them correctly.
GRI: The comprehensive impact reporter
The Global Reporting Initiative (GRI) Standards are the world's most widely used sustainability reporting framework. First published in 1997, GRI is built on a stakeholder-centric model: the primary audience is the full range of stakeholders — investors, employees, communities, NGOs, regulators, and the public.
GRI's core philosophy
A company using GRI should report on all material impacts, regardless of whether those impacts affect the company financially. GRI measures what the company does to the world — not just what the world does to the company's balance sheet.
- Framework: Universal Standards + Sector Standards + Topic Standards
- Coverage: Economy, environment, human rights, labour, anti-corruption, social
- Audience: Multi-stakeholder (investors, NGOs, communities, regulators, public)
- Materiality: Impact materiality — what matters to affected stakeholders
- Comparable: Moderate — sector standards improve comparability but many topics allow flexible metrics
- Mandatory: Not legally required in most jurisdictions, but ESRS (CSRD) is interoperable with GRI
SASB: The financially material, industry-specific standard
The Sustainability Accounting Standards Board (SASB) Standards — now integrated under the IFRS Foundation — cover 77 industries across 11 sectors. SASB's approach is explicit: only disclose ESG information that is reasonably likely to constitute material information for investors. This financial materiality lens makes SASB the most comparable and analyst-friendly of the three.
SASB's unique value
Because SASB metrics are industry-specific, they are actually comparable across companies in the same industry. A software company's material SASB topics (data privacy, employee diversity) are completely different from an oil company's (GHG emissions, water management, spill prevention). This makes SASB the most useful tool for sector-level ESG peer analysis.
- Framework: 77 industry-specific standards organised by 11 sectors
- Coverage: Only financially material ESG topics per industry
- Audience: Financial investors seeking comparable, decision-useful data
- Materiality: Financial materiality — what affects enterprise value
- Comparable: High — metrics are standardised within each industry
- Mandatory: Not legally required; increasingly referenced in SEC disclosure guidance
ISSB: The global investor-focused baseline
The International Sustainability Standards Board (ISSB), established under the IFRS Foundation in 2021, published IFRS S1 (General Requirements) and IFRS S2 (Climate-related Disclosures) in June 2023. ISSB represents the most significant attempt to create a globally consistent, investor-grade sustainability reporting baseline that can be adopted or referenced by national regulators worldwide.
- IFRS S1: General sustainability-related financial disclosures (modelled on TCFD)
- IFRS S2: Climate-related disclosures (aligned with and superseding TCFD)
- Audience: Capital markets investors and regulators
- Materiality: Financial materiality — information useful to investors
- Comparable: High by design — cross-jurisdictional comparability is the core goal
- Mandatory: Adopted or referenced in UK, Australia, Japan, Singapore, Canada; under consideration in EU as CSRD building block
ISSB and TCFD
ISSB effectively absorbed and superseded the TCFD framework. TCFD was disbanded in 2023 after confirming that ISSB's IFRS S2 fully incorporated its recommendations. Companies reporting under IFRS S2 satisfy TCFD requirements.
Side-by-side comparison
| Dimension | GRI | SASB | ISSB |
|---|---|---|---|
| Primary audience | All stakeholders | Financial investors | Capital markets / regulators |
| Materiality concept | Impact materiality | Financial materiality | Financial materiality |
| Industry-specific? | Yes (Sector Standards) | Yes (core design) | No (principles-based) |
| Comparable metrics? | Moderate | High | High |
| Narrative + data? | Both | Mostly data | Both |
| Climate focus | One topic among many | Per-industry climate topics | Dedicated S2 standard |
| Adoption scale | ~14,000 reporters | ~7,000 reporters | Growing rapidly post-2023 |
| CSRD compatible? | Highly (ESRS based on GRI) | Referenced in ESRS | Building block for ESRS |
Choosing the right combination
Most large companies use more than one standard. The practical question is which to prioritise and how to reconcile overlapping requirements.
Decision framework by use case
| Use case | Recommended approach |
|---|---|
| EU large company, CSRD-mandated | Lead with ESRS — use GRI interoperability table to satisfy GRI users simultaneously. Add SASB for investor-specific comparability. |
| US public company, SEC climate rule | Lead with IFRS S2 / ISSB — satisfies SEC climate disclosure and TCFD simultaneously. Add SASB for your sector metrics. |
| Global listed company, multiple regulators | Use ISSB as baseline + SASB for sector metrics + GRI Topic Standards for specific stakeholder audiences. Map all three in an index. |
| SME not yet mandated | Start with GRI Essentials level + relevant SASB industry standard. Focus on 10–15 most material metrics rather than comprehensive coverage. |
| Impact investor / ESG fund | Require SASB for comparability + GRI for supply chain and social impact + SFDR PAI indicators for ESRS S1/S2 coverage. |
| Startup / B Corp aspirant | GRI Essentials provides a credible starting point. Add SASB industry standard for investor readiness. |
How they interact with each other
GRI and ISSB both incorporate financial materiality concepts but weigh them differently. EFRAG has published a detailed interoperability mapping between ESRS (CSRD) and GRI Standards, confirming that companies can use a single report to satisfy both. SASB has been integrated under IFRS Foundation, and ISSB has confirmed it will consider incorporating sector-specific metrics from SASB into future versions of IFRS S1/S2.
The practical approach
For most companies, the pragmatic path is: (1) Do your double materiality assessment first — this identifies which topics are material under any framework. (2) Use GRI topic standards for comprehensive impact coverage. (3) Use SASB to identify the specific metrics your investors care about. (4) Use ISSB/IFRS S2 to ensure your climate disclosures are investor-grade. Report once, map to all three in an index table.