Companies subject to CSRD must report to the European Sustainability Reporting Standards (ESRS). Companies outside CSRD scope have a choice of voluntary frameworks including GRI, SASB, CDP, and others. Understanding how these relate — and where they overlap — helps companies avoid duplicating work and build a reporting approach that satisfies multiple audiences.
The Three Main Frameworks
ESRS (European Sustainability Reporting Standards)
What it is: The mandatory reporting standards developed by EFRAG under CSRD. Legally binding for in-scope EU companies.
Scope: 12 topical standards covering environment (E1-E5), social (S1-S4), and governance (G1), plus two cross-cutting standards (ESRS 1 and ESRS 2).
Approach: Principle-based with specific disclosure requirements. Companies must apply double materiality to determine which topics require full disclosure.
Assurance: Third-party limited assurance required; moving towards reasonable assurance.
Who uses it: All CSRD-reporting companies. This is not a choice — CSRD mandates ESRS.
GRI (Global Reporting Initiative)
What it is: The most widely used voluntary sustainability reporting framework globally, developed by an independent international standards body.
Scope: Universal standards (GRI 1, 2, 3 on foundation and material topics) plus Topic Standards (GRI 200-400 series covering economic, environmental, and social topics).
Approach: Reporting on material topics identified through stakeholder engagement, using specific GRI disclosures for each topic.
Assurance: Optional — companies may commission external assurance but it is not required.
Who uses it: Companies globally, from SMEs to multinationals, across all sectors. Approximately 10,000 organisations report to GRI.
SASB (Sustainability Accounting Standards Board)
What it is: Sector-specific standards developed originally for US-listed companies, now maintained by IFRS Foundation alongside ISSB standards.
Scope: Industry-specific standards across 77 sectors. Focus on financially material sustainability topics.
Approach: Financial materiality lens — focused on sustainability topics that affect financial performance.
Assurance: Optional.
Who uses it: Companies in markets with investor-led sustainability disclosure expectations, particularly US-listed companies and their supply chains.
How They Relate to Each Other
ESRS and GRI: High Alignment
EFRAG explicitly designed ESRS to maximise interoperability with GRI. The result:
- Most ESRS disclosures have a GRI equivalent. EFRAG published an interoperability index mapping ESRS requirements to GRI Topic Standards.
- Companies reporting to GRI will cover much of ESRS automatically — if they report on climate (GRI 305), own workforce (GRI 401-407), business conduct (GRI 205-207).
- Key differences: ESRS requires a formal double materiality assessment with a specific methodology. GRI's materiality is based on stakeholder engagement without a prescribed methodology. ESRS requires machine-readable tagging (ESEF). GRI does not.
- For CSRD-reporting companies: GRI reporting is no longer sufficient — ESRS is mandatory. But previous GRI work reduces the incremental effort.
ESRS and ISSB/IFRS S1/S2
The ISSB (International Sustainability Standards Board) issued IFRS S1 (general requirements) and IFRS S2 (climate) in June 2023, which are being adopted in various jurisdictions.
- ESRS E1 (climate) aligns substantially with IFRS S2 (both are based on TCFD)
- ESRS covers a broader scope than ISSB — ESRS includes impact materiality; ISSB focuses on financial materiality
- For companies with global operations: many ESRS climate disclosures satisfy ISSB/IFRS S2 requirements simultaneously
Which Standard to Use: A Decision Framework
| Company type | Standard | Rationale |
|---|---|---|
| EU company, in CSRD scope | ESRS (mandatory) | No choice — CSRD requires ESRS |
| EU company, below CSRD thresholds, seeking voluntary reporting | GRI or ESRS VSME | GRI is most widely recognised globally; VSME when available is designed for EU SMEs |
| EU company, below CSRD thresholds, targeted at EU institutional investors | ESRS voluntary or GRI | ESRS voluntary signals readiness for future mandatory reporting |
| US company, SEC climate rules in scope | IFRS S2 / TCFD-aligned | SEC rules closely align with TCFD; consider ESRS E1 in parallel if EU revenue is significant |
| Non-EU company, in CSRD Wave 4 scope | ESRS (mandatory for EU consolidation) | Wave 4 companies report ESRS for EU operations; may use other standards for global reporting |
| Non-EU company, not in CSRD scope, selling to EU enterprises | GRI at minimum | EU customers' value chain reporting needs basic sustainability data; GRI aligns with ESRS |
Practical Approach for Companies Starting from Scratch
If you are in Wave 2 of CSRD (report due 2026) and have not yet started:
Year 1 priority: Complete the double materiality assessment. This determines which ESRS topics you must report on and is the prerequisite for everything else.
Year 1-2: Build data collection systems for your material topics. ESRS disclosures require quantitative metrics that most companies do not currently track systematically.
Year 2: Prepare the first ESRS report and engage an assurance provider.
If you previously reported to GRI: map your existing GRI disclosures to ESRS using the EFRAG interoperability index. Identify gaps — areas where ESRS requires disclosures that GRI does not. Focus your additional work on those gaps.