GRI and ISSB: Two Lenses, One Clearer Picture

If you have ever felt torn between reporting frameworks, you are not alone. I have watched finance teams spend weeks debating whether to follow GRI or ISSB, as if choosing one meant abandoning the other. Here is the truth: they answer different questions. GRI asks, "How does your organization affect the world?" ISSB asks, "How does the world affect your organization's finances?" Both matter. And increasingly, they are built to fit together.

What GRI actually asks you to report

The GRI Standards help organizations report their most significant impacts on the economy, environment and people—including human rights impacts. That impact focus is deliberate. It differs from reporting designed primarily for capital-market users. If you are new to GRI, start with the 2021 Universal Standards: GRI 1: Foundation, GRI 2: General Disclosures and GRI 3: Material Topics. They apply across organizations and have been effective for information published since 1 January 2023.

Under GRI, a "material topic" is one representing your most significant impacts on the economy, environment and people. Stakeholder engagement informs how you identify and assess those impacts. Notice what is not a separate test: stakeholder influence on your decisions. You engage stakeholders to understand impacts, not to rank who shouts loudest.

Materiality, double materiality, and why the distinction matters

In common reporting usage, double materiality means considering both impact materiality—your impacts on people and the environment—and financial materiality—sustainability-related risks and opportunities that affect you financially. GRI's lens is the impact side. ISSB's lens is the financial side. They address distinct, complementary information needs.

ISSB's financial-materiality lens, set out in IFRS S1 and S2, focuses on sustainability-related risks and opportunities reasonably expected to affect an entity's prospects—including cash flows, access to finance or cost of capital over the short, medium or long term. That is a different question from GRI's, and it deserves a different evidence trail.

For valuers, auditors and finance teams, the practical discipline is simple: do not treat GRI impact materiality as interchangeable with ISSB financial materiality. Identify and evidence each lens separately, then map disclosures where requirements overlap.

How GRI and ISSB complement each other

You can use GRI to report impacts and ISSB standards to report financially material sustainability-related information. The IFRS Foundation and GRI have agreed to pursue direct interoperability and align common disclosures while retaining the different purposes of the standards. That is not a slogan—it shows up in practical tools. ISSB and GRI published joint mapping on greenhouse-gas emissions, covering how GRI 305 and IFRS S2 disclosures relate for Scope 1, Scope 2 and Scope 3 emissions.

So when someone asks whether you should follow GRI or ISSB, the better answer is: use each for its purpose, and map where they overlap.

What this means in Hong Kong right now

Hong Kong is moving quickly. HKICPA issued HKFRS S1 and HKFRS S2 on a full-alignment basis with ISSB standards, with voluntary application effective from 1 August 2025. HKEX climate requirements based on IFRS S2 took effect for financial years beginning on or after 1 January 2025. Scope 1 and Scope 2 emissions disclosure is mandatory for all listed issuers; other new climate requirements apply on a "comply or explain" basis for Main Board issuers, with mandatory application for LargeCap issuers from financial years beginning on or after 1 January 2026.

The December 2024 roadmap sets a path toward ISSB-standard reporting by publicly accountable entities, with large PAEs targeted to adopt no later than 2028. HKEX plans to consult in 2027 on mandating Hong Kong Sustainability Disclosure Standards for listed PAEs.

If you are preparing now, here is a practical sequence:

• Identify your impacts using GRI 3, engaging stakeholders to assess significance.
• Identify sustainability-related risks and opportunities using IFRS S1 and S2 financial materiality.
• Map overlapping disclosures—especially greenhouse gases under GRI 305 and IFRS S2—so you collect data once and report it twice.
• Document your evidence separately for each lens, so auditors and valuers can trace both.

None of this requires choosing sides. It requires clarity about which question you are answering—and the discipline to answer each one well.

For a fuller walkthrough, see ESG Reporting Made Simple: A Practical Guide to GRI Standards. For jurisdiction context, see the IFRS Hong Kong SAR profile and the Hong Kong roadmap. On interoperability, see the ISSB interoperability paper and PwC's roadmap analysis. For GRI's own guidance, see the Universal Standards FAQs.