Raymond Cheung
Chartered Actuary · CRO · Board Adviser · Singapore
Straits Times Index constituents stay on the original timeline for mandatory Scope 3 emissions reporting from FY2026, even after SGX RegCo pushed the requirement back for every other listed company. With only 29% of Singapore-listed issuers currently reporting Scope 3 at all, STI boards that treat this as a data problem for the sustainability team, rather than a governance decision for the board, will run out of runway before their next annual report.
I've sat in more than one board sustainability committee meeting where Scope 3 was discussed as a future problem — something to build capability toward over the next few years, once Scope 1 and 2 reporting had matured. For companies inside the Straits Times Index, that runway has already run out. When SGX RegCo extended the timeline for mandatory value-chain emissions reporting in 2024, it built a three-tier system by company size and index membership — and it deliberately left STI constituents on the original schedule. Scope 3 is mandatory for STI companies from FY2026. For a board with a December year-end, that is effectively now.
The tiering means STI boards don't get the grace period everyone else just got
The revised framework splits listed companies into three groups: STI constituents, non-STI companies above roughly S$1 billion in market capitalisation, and everyone below that. All listed companies must disclose Scope 1 and 2 emissions from FY2025 — that part is uniform. But ISSB-aligned climate disclosures more broadly are deferred to FY2028 for larger non-STI companies and FY2030 for smaller ones, and Scope 3 stays voluntary for both of those tiers in the meantime. STI constituents got none of that relief. The regulator's logic is straightforward — the thirty largest, most liquid companies on the exchange are the ones institutional investors and index funds most need comparable value-chain data from — but it means the boards facing the hardest reporting category are the ones with the least additional time to prepare for it.
“STI boards facing Scope 3 don't get to say the data is hard to get. That is exactly why the exchange put them on the original schedule.”
The compliance gap is exactly where the mandate now lands
A review of Singapore-listed sustainability reports found 87% of issuers disclosing Scope 2 emissions and 80% disclosing Scope 1 — but only 29% disclosing Scope 3. That gap exists for a structural reason: Scope 3 covers purchased goods and services, business travel, employee commuting, waste disposal, and the use and disposal of sold products — categories that, combined, typically make up 70% or more of a company's total footprint, and that no single internal function fully owns. A sustainability team can pull utility bills for Scope 1 and 2. It cannot unilaterally produce supplier-level emissions data, employee commuting patterns, or product end-of-life assumptions without procurement, HR, finance, and often the supply chain itself cooperating on definitions the board has never actually settled.
Why this is a board decision, not a data-collection exercise
The mistake I see most often is delegating Scope 3 entirely to the sustainability function as though it were a technical reporting task. It isn't. Before any data gets collected, someone has to decide which Scope 3 categories are material enough to report on and which can be reasonably excluded — a judgement call with real disclosure risk attached if it's made by a junior team without board sign-off. Someone has to decide what estimation methodology is used where supplier-level data doesn't exist yet, because for most companies it won't in year one. And someone has to start planning now for external limited assurance over Scope 1 and 2, which becomes mandatory from FY2029 — a deadline that sounds distant but requires the underlying data systems to be assurance-ready years before an auditor ever looks at them.
- Has the board — not the sustainability team alone — signed off on which Scope 3 categories are material to this business and documented why any are excluded?
- Is there a named owner in procurement, HR, or finance for each material category's data, or does the sustainability team still own all of it by default?
- Has the company engaged, or started evaluating, an external assurance provider ahead of the FY2029 mandatory assurance requirement for Scope 1 and 2?
- Does the sustainability or ESG committee report Scope 3 progress to the full board as a standing item, or only surface it once a year when the annual report is being drafted?
None of this is a call to panic. It's a call to sequence the work correctly. The STI boards that get ahead of FY2026 will have spent the remaining months of this year making the judgement calls — materiality, methodology, ownership — that actually require board input, so that what's left for the sustainability team is execution rather than guesswork. The ones that wait for the annual report drafting cycle to force the conversation will discover, in public, that 29% Scope 3 disclosure rate exists for a reason, and that reason was never really about data.
Common Questions
Which Singapore-listed companies must report Scope 3 emissions from FY2026?
Straits Times Index (STI) constituents remain on the original mandatory timeline for Scope 3 (value-chain) emissions reporting from FY2026. Non-STI companies above roughly S$1 billion in market capitalisation and smaller listed companies had their broader ISSB-aligned climate disclosure timelines deferred to FY2028 and FY2030 respectively, with Scope 3 remaining voluntary for those tiers in the interim. All listed companies must still disclose Scope 1 and Scope 2 emissions from FY2025.
What should an STI board do if it can't get reliable Scope 3 data from suppliers?
Use recognised estimation methodologies for categories where primary supplier data isn't yet available, and disclose the methodology and its limitations transparently rather than omitting the category. The board's job is to sign off on which categories are material and what estimation approach is being used, and to task management with improving data quality — usually starting with the largest suppliers by spend — in subsequent reporting years.
Does Scope 3 emissions reporting require external assurance in Singapore?
Not yet. External limited assurance is currently mandated for Scope 1 and Scope 2 emissions from FY2029 for listed companies. Scope 3 assurance requirements have not been mandated on the same timeline, but boards preparing for FY2026 Scope 3 disclosure should build data systems now that will also support Scope 1 and 2 assurance readiness ahead of that FY2029 deadline.
About the author
Raymond Cheung is a Chartered Actuary, C-suite executive and board adviser with more than 20 years of experience across Asia in risk management, insurance, ESG and corporate governance. He is the CEO of CER Consultancy and an accredited trainer at SMU Academy and the Singapore College of Insurance.