For most companies, the emissions that matter most are the ones they do not own. Scope 3 emissions<\/strong> \u2014 the indirect emissions across a company’s value chain \u2014 typically dwarf its direct (Scope 1) and energy (Scope 2) emissions, often accounting for the large majority of the total footprint. As IFRS S2, CBAM and ESG ratings increasingly demand value-chain data, Scope 3 has moved from optional to unavoidable for Thai companies. This guide explains what Scope 3 covers, why it matters, and how to approach it.<\/p>\n\n\n\n The GHG Protocol divides emissions into three scopes. Scope 1<\/strong> is direct emissions from owned or controlled sources. Scope 2<\/strong> is indirect emissions from purchased energy. Scope 3<\/strong> is everything else \u2014 the indirect emissions across the value chain, both upstream (suppliers, purchased goods, logistics) and downstream (use and end-of-life of products). Because it spans the whole value chain, Scope 3 is usually the largest and the hardest to measure.<\/p>\n\n\n\n The GHG Protocol defines 15 Scope 3 categories<\/strong>, split into upstream and downstream:<\/p>\n\n\n\n Not all categories are relevant to every company. The first task is a screening to identify which categories are material to your business.<\/p>\n\n\n\n Three forces are making Scope 3 unavoidable for Thai companies:<\/p>\n\n\n\n A GHG inventory<\/a> that stops at Scope 2 no longer meets the bar.<\/p>\n\n\n\n Scope 3 is estimated, not metered, so method and transparency matter as much as the number:<\/p>\n\n\n\n Credible Scope 3 disclosure is about transparency as much as totals. Report which categories are included and excluded and why; the methods and data quality used; the emission factors applied; and any reduction targets. Under IFRS S2, this feeds directly into your climate metrics and targets. Disclosing a partial but honest Scope 3 inventory, with a plan to improve it, is far stronger than omitting it \u2014 and it should read identically across your Thai and English disclosure<\/a>.<\/p>\n\n\n\n For Thai issuers, Scope 3 figures, category boundaries and methodology notes must reconcile exactly across the Thai and English versions of the disclosure. A boundary described one way in Thai and another in English undermines the credibility of the whole inventory \u2014 which is why value-chain data is best handled within a single, reconciled bilingual ESG advisory<\/a> process.<\/p>\n\n\n\n\n A full 15-category Scope 3 inventory is a multi-year journey, so the first cycle is about focus, not completeness. Start by identifying the two or three categories that dominate your footprint \u2014 for a manufacturer that is usually purchased goods and services<\/em>; for a producer of energy-using products it is often use of sold products<\/em>. Estimate these first with a spend-based or average-data method, be transparent that they are estimates, and begin engaging your largest suppliers for primary data. A focused, honest inventory of the material categories is far more useful \u2014 to investors, raters and your own decarbonisation planning \u2014 than a thin attempt to cover all fifteen at once.<\/p>\n\n\n\n Measurement is only half the story; investors and ratings increasingly look for reduction targets<\/strong> that include the value chain. Frameworks such as the Science Based Targets initiative (SBTi) generally require companies to set Scope 3 targets where those emissions are a significant share of the total. Doing so means fixing a base year, choosing an appropriate metric (absolute or intensity), and \u2014 critically \u2014 building supplier engagement into the plan, because most of the reductions sit outside your direct control. For Thai exporters, credible value-chain targets are also becoming a commercial expectation from international customers, not just a disclosure line item.<\/p>\n\n\n\n\n Scope 3 will only grow in importance as IFRS S2 adoption deepens and value-chain expectations harden. The companies that start now \u2014 focusing on their material categories, being transparent about method, and reconciling the numbers across Thai and English \u2014 will be ready when disclosure of value-chain emissions moves from good practice to baseline expectation. Starting imperfectly, and improving each cycle, beats waiting for perfect data.<\/p>\n\n\n\n\n Because Scope 3 is estimated and spans so many categories, it is easy to get wrong. The recurring mistakes:<\/p>\n\n\n\n Avoiding these is less about sophistication than about discipline: define the boundary, document the method, and improve the data where it matters most.<\/p>\n\n\n\n\n \ud83d\udcd8 Free resource:<\/strong> Explore The FTSE 2026 Playbook Library<\/a> \u2014 Othello’s ESG disclosure playbook plus focused editions for Thai banks, energy, property, healthcare, technology and more.<\/p>\n\n\n Othello International is a Bangkok-based bilingual (EN\u2194TH) technical translation and ESG advisory firm. Related specialist services:<\/p>\n\n\n\nWhat Scope 3 Emissions Are<\/h2>\n\n\n\n
The 15 Scope 3 Categories<\/h2>\n\n\n\n
Why Scope 3 Matters Now<\/h2>\n\n\n\n
How to Measure Scope 3<\/h2>\n\n\n\n
What to Disclose<\/h2>\n\n\n\n
The Bilingual Dimension<\/h2>\n\n\n\n
Where Thai Companies Should Start<\/h2>\n\n\n\n
Setting Scope 3 Reduction Targets<\/h2>\n\n\n\n
Common Scope 3 Mistakes to Avoid<\/h2>\n\n\n\n
Related services from Othello International<\/h2>\n\n\n\n