ESG reporting frameworks compared: GRI, TCFD, ISSB, ESRS

GRI (Global Reporting Initiative), TCFD (Task Force on Climate-related Financial Disclosures), ISSB (International Sustainability Standards Board), ESRS (European Sustainability Reporting Standards) and SASB (Sustainability Accounting Standards Board) are five acronyms with different roles in sustainability reporting. Navigating this landscape is one of the most common points of confusion for businesses preparing to report. This guide maps them clearly and explains which applies to you.

Why are there so many frameworks?

The proliferation of sustainability reporting frameworks reflects the fact that different stakeholder groups developed them for different purposes. Investors wanted financial materiality: what sustainability risks affect the bottom line? NGOs (non-governmental organisations) and standard-setters wanted impact materiality: what harm is your business doing? Regulators wanted mandatory, comparable, auditable disclosure. Each group created its own framework, and the result was fragmentation.

That fragmentation is beginning to resolve. The ISSB is building a global investor-focused baseline. CSRD (Corporate Sustainability Reporting Directive)'s ESRS are built partly on GRI and TCFD foundations. Convergence is happening, but it is not complete, and many large organisations still need to navigate multiple frameworks simultaneously.

GRI: Global Reporting Initiative

GRI is the oldest and most widely used sustainability reporting framework, with roots in the late 1990s. GRI standards cover a wide range of environmental, social and governance topics in detail and take an impact materiality perspective: reporting on your organisation's effects on the world, regardless of financial materiality.

GRI standards are voluntary but widely adopted globally. CSRD's ESRS are partially interoperable with GRI, meaning companies that have already been reporting under GRI have a head start on CSRD compliance. GRI publishes a mapping document showing where ESRS requirements align with GRI disclosures. Our standalone GRI Standards explained guide goes deeper into impact materiality, the Universal Standards and where GRI differs from ESRS and ISSB.

TCFD: Task Force on Climate-related Financial Disclosures

TCFD was established by the Financial Stability Board in 2015 and published its final recommendations in 2017. It takes a financial materiality perspective focused specifically on how climate risks and opportunities affect a company's financial performance. Our standalone TCFD explained guide goes deeper into the UK reporting rules, four-pillar structure and move toward UK Sustainability Reporting Standards (UK SRS).

TCFD uses a four-pillar structure: governance (who oversees climate risk?), strategy (how does climate affect your business model?), risk management (how do you identify and manage climate risk?), and metrics and targets (what do you measure and what are your goals?).

Disclosure aligned with TCFD is now mandatory for many UK companies under UK financial regulations, and forms the basis of the climate-related disclosure requirements in the ESRS climate standard.

ISSB: International Sustainability Standards Board

The ISSB was established by the IFRS Foundation in 2021 to create a global baseline for investor-focused sustainability disclosure. It published IFRS S1 (general sustainability disclosure requirements) and IFRS S2 (climate-related disclosures) in June 2023. Our standalone guide to ISSB, IFRS S1 and IFRS S2 explains that global baseline in more detail.

IFRS S2 is explicitly built on TCFD and incorporates TCFD's four-pillar structure. ISSB standards take a financial materiality perspective and are designed for capital markets disclosure. The UK government has developed UK Sustainability Reporting Standards (UK SRS) based on ISSB standards; our detailed guide to UK SRS and IFRS S2 climate disclosures explains how those standards affect reporting readiness.

ESRS: European Sustainability Reporting Standards

ESRS are the mandatory reporting standards under CSRD. They are among the most comprehensive sustainability reporting standards currently in operation, covering environmental, social and governance topics under a double materiality framework that combines financial and impact materiality.

ESRS 1 and ESRS 2 set general requirements; sector-specific ESRS are under development. The ESRS climate standard covers climate change and is closely aligned with TCFD. ESRS has interoperability with GRI and the ISSB standards.

SASB: Sustainability Accounting Standards Board

SASB (now merged into the ISSB) published industry-specific sustainability accounting standards focused on financial materiality. SASB standards tell you which ESG (environmental, social and governance) topics are most financially material for 77 specific industries - useful for identifying what to prioritise in your ESG reporting.

Which frameworks does your business need?

For most UK businesses, the practical answer is:

If you are a large UK company already subject to mandatory TCFD reporting: continue with TCFD and prepare for UK SRS adoption.

If you have significant EU operations and meet the CSRD thresholds: ESRS is mandatory. Using GRI as a reporting foundation is efficient given the interoperability.

If you are a UK small and medium-sized enterprise (SME) reporting voluntarily: GRI is the most widely understood voluntary framework. A report aligned with GRI will also be compatible with most investor and supply chain requirements.

How to choose the reporting sequence

The safest sequence is to start with the legal trigger, then the audience, then the evidence. A company with direct CSRD exposure should not begin by choosing a voluntary framework. It should map scope, material topics and ESRS requirements first. A company preparing for lenders or investors may begin with climate and financial-risk disclosure shaped by ISSB. A supplier responding to customer questionnaires may need a lighter evidence file that covers emissions, policies, workforce data and claims support.

The frameworks are less confusing when they are treated as tools for different questions. GRI helps answer "what impacts do we have?" TCFD and ISSB help answer "how do sustainability risks affect enterprise value?" ESRS asks both questions under double materiality. SASB helps identify financially material industry topics. California's SB 253 and SB 261 climate disclosure laws show the same point in statutory form: emissions data, climate-risk reporting and implementation guidance need to be mapped together. The right answer may be one framework, but for larger companies it is often a reporting architecture rather than a single logo.

Practical read-order

If the starting point is EU reporting, read CSRD explained and then the CSRD hub. If the starting point is climate disclosure, read TCFD explained and UK SRS and IFRS S2. If the starting point is evidence quality, use the ESG data room checklist and limited vs reasonable assurance guide.

Key takeaway

GRI is the established global standard for voluntary disclosure. TCFD is the investor-focused climate framework, now mandatory for many UK companies. ISSB is the emerging global baseline for capital market sustainability disclosure. ESRS is the EU mandatory framework under CSRD. They are converging - but for now, which frameworks apply to you depends on your size, listing status, and EU exposure.

Reporting frameworks FAQ

Should a company use GRI or ISSB?

It depends on the audience. GRI is stronger for broad stakeholder and impact reporting. ISSB is designed as an investor-focused global baseline. Some companies will use both, especially where they need to satisfy investors and wider sustainability stakeholders.

Is TCFD still relevant after ISSB?

Yes. IFRS S2 builds on the TCFD structure, so the four pillars remain useful. Companies with existing TCFD processes are better placed to prepare for reporting based on ISSB.

How does ESRS differ from ISSB?

ESRS uses double materiality and covers a broad set of environmental, social and governance topics. ISSB is focused on sustainability-related financial disclosure for capital markets.

Useful source links

• Global Reporting Initiative Standards
• IFRS Sustainability Standards
• EFRAG: European Sustainability Reporting Standards
• TCFD explained
• UK SRS and IFRS S2 climate disclosures