Hong Kong ESG Reporting 2026: Does It Apply to Your Company?

2026 is the first financial year in which Hong Kong's largest listed issuers must report climate disclosures on a fully mandatory basis — and the first year that requirement starts pulling data requests down through their supply chains.

Here is who has to report, when, and whether any of it reaches a company that is not listed.

The short answer

Two frameworks, often confused

The HKEX ESG Reporting Code (Appendix C2) is what binds listed issuers today. In April 2024 HKEX finalised a new Part D — the climate requirements — modelled on IFRS S2 and covering the four ISSB pillars: governance, strategy, risk management, and metrics and targets.

The HKFRS Sustainability Disclosure Standards (HKFRS S1 and S2) were published by the HKICPA in December 2024, fully aligned with the ISSB standards, effective 1 August 2025. They are available for voluntary use but are not mandatory unless and until a regulator requires them.

The distinction matters: what binds listed issuers right now is Part D, not the HKFRS standards.

Who must report, and when

LargeCap issuers. Main Board issuers that are Hang Seng Composite LargeCap Index constituents must report against the full climate requirements on a mandatory basis for financial years beginning on or after 1 January 2026 — including Scope 3 emissions, scenario analysis, transition planning and the financial effects of climate risk.

One definitional point that catches people out: a LargeCap issuer is one that was an index constituent throughout the year immediately before the reporting year. Membership during 2025 determines mandatory reporting for financial year 2026, with the report published in 2027.

Other Main Board issuers. Comply-or-explain against Part D for financial years beginning on or after 1 January 2025 — but note the floor: Scope 1 and Scope 2 emissions are mandatory for every listed issuer regardless of any explanation offered.

GEM issuers. Same mandatory Scope 1 and 2 requirement; the wider Part D disclosures are encouraged voluntarily.

Private and non-listed companies. There is currently no law requiring a private Hong Kong company to publish an ESG report. If someone tells you it is compulsory, ask them to point at the rule.

The timeline ahead

Why this reaches companies that are not listed

Scope 3 is someone else's Scope 1. When a LargeCap issuer must disclose Scope 3 on a mandatory basis, it needs emissions data from across its value chain — meaning from its suppliers. If you sell to or provide services to a listed group, expect a questionnaire, increasingly with a deadline attached.

Banks and insurers are adding sustainability questions to onboarding and renewal paperwork. Large corporate and government-related tenders are adding sustainability criteria. And customers in the EU or Mainland China bring their own disclosure obligations, which arrive at your desk as data requests.

The realistic risk for a Hong Kong SME in 2026 is not a regulatory penalty. It is being dropped from a supply chain because the buyer needed a number you could not produce.

Assurance is the next thing coming

The HKICPA published a local sustainability assurance standard aligned with ISSA 5000 in March 2025, and updated its Code of Ethics in October 2025 to cover sustainability assurance. The Accounting and Financial Reporting Council is working with financial regulators on Hong Kong's assurance regime.

The practical implication: sustainability data is moving toward the same standard of evidence as financial data. Figures assembled from estimates in a spreadsheet will eventually have to survive being tested.

What to do now

LargeCap issuers: the transition period is over. Document the Scope 3 boundary, secure supplier data, and write down scenario assumptions rather than keeping them in someone's head.

Other Main Board issuers: you have comply-or-explain room, but the explanation has to be a real one. The runway to mandatory reporting is finite.

GEM issuers: measure Scope 1 and 2 properly and consistently. That is the mandatory floor and the foundation for everything else.

Private companies: do not commission a report you do not need. Do calculate Scope 1 and Scope 2 and keep the working papers, so the first customer questionnaire is answered from records rather than guesswork.

Two mistakes worth avoiding across all four: treating this as a reporting exercise rather than a governance one — board oversight sits at the centre of both the HKEX code and the ISSB standards — and buying a report instead of building a repeatable data process. The first is an expense; the second survives assurance.

Summary

For financial years beginning on or after 1 January 2026, LargeCap issuers report climate disclosures on a fully mandatory basis, Scope 3 included. Other Main Board issuers remain on comply-or-explain, with Scope 1 and 2 mandatory for every listed issuer. GEM issuers report the wider requirements voluntarily. Private companies face no statutory obligation.

But as mandatory reporting works its way up the market, data requests work their way down it — and a private company's real deadline is set by its largest customer, not by a regulator.

This article reflects the position as at August 2026 and is provided for general information only. It is not legal or professional advice. Requirements should be confirmed against the current HKEX Listing Rules, HKICPA pronouncements and any regulator guidance applicable to your entity.

SMEBro provides company formation, accounting, audit, tax filing and company secretarial services to Hong Kong SMEs. If you are working out your reporting obligations — or preparing for a customer's sustainability questionnaire — our consultants are happy to talk it through.