CBAM Verification Opened on 1 September — and All Three Documents Must Be in English

On 1 September 2026 a door opened in Brussels that most Thai exporters will never see. Verifiers accredited under the EU’s Carbon Border Adjustment Mechanism can now get into the CBAM Registry. The European Commission’s guidance of 24 August says they must register within two months of accreditation, “but not before 1 September 2026”, and that “starting from January 2027, they will issue verification reports in the CBAM Registry.” The Commission expects the first accredited verifiers “around September 2026”.

That matters in Thailand for a plain reason. The EU imported 201,980 tonnes of CBAM-scope steel from Thailand in the first half of 2026, more than double the same period of 2025, according to our analysis of Eurostat’s Comext data. The biggest lines by value were hot-rolled flat steel and screws, bolts and nuts. Every tonne carries embedded emissions that an EU importer must declare by 30 September 2027, using either your verified figures or the Commission’s default values.

What actually opened on 1 September

Registry access is the plumbing that makes verified data usable. Your emissions report, once verified, reaches the EU importer (the authorised CBAM declarant) through the Registry. The same portal lets non-EU operators register their installations, which the Commission describes as “recommended, but currently voluntary.”

Only an EU or EEA national accreditation body can accredit a CBAM verifier. The Commission calls these bodies “the sole stakeholders competent to grant accreditation for the CBAM.” A verification company based outside the EU may apply to one, but the guidance is explicit that accreditation bodies “are not obliged to offer services to non-EU companies.” Accreditation is to EN ISO/IEC 17029, applied together with EN ISO 14065. A body’s registration with TGO in Thailand does not, on its own, make it a CBAM verifier.

The first verification needs someone at your plant

The Commission’s guidance is candid that “the CBAM does not provide for a firm deadline regarding the verification of an emissions report.” The deadline is set by the calendar instead. Because the reporting period runs from 1 January to 31 December, verification “cannot be concluded before January of the subsequent year.” Importers need time to compile declarations and buy certificates before 30 September, which is where the mid-August expectation comes from.

The site visit is the part that most changes the workload. Under the verification rules a verifier may visit virtually only if, among other conditions, a physical site visit was carried out “during the reporting period immediately preceding the current reporting period.” A plant being verified for the first time has no preceding visit. On our reading of those conditions, the first CBAM verification of a Thai installation means a verifier physically on site.

Fasteners and other complex goods add a dependency. If you make bolts from purchased wire rod, your report needs your suppliers’ verified figures for those precursors. The Commission’s own worked example has the operator finishing the emissions report by the end of June for verification by the end of July, and substituting default values for any precursor report that has not arrived. For a re-roller, most of the embedded emissions sit in the steel it buys. Verifying your own plant while the wire rod stays on a default value captures only part of the saving.

Not everyone expects 2026 data to make it through at all. EFDA, the European trade body for fastener distribution, wrote in its 2026 CBAM cost guide that it is “currently highly unlikely that actual emission data can be used for imports made in 2026”, pointing to the shortage of accredited verifiers and the on-site visits they must make. If that proves right, 2026 becomes a monitoring year, and the case for verified data starts with 2027 imports, when the default mark-up doubles to 20%.

Three documents, one language

The CBAM Regulation itself, (EU) 2023/956, contains no language rule. The language rules sit one level down, in the implementing acts and the guidance, and they point the same way three times.

This is where language stops being a presentation question. A verifier samples the underlying records: fuel invoices, meter logs, production and precursor purchase records. At a Thai plant most of those are in Thai. The verified report is in English. The two have to agree, and any gap between them is found by an auditor, not a reader. The Commission itself advises keeping a local-language version of the monitoring plan, because it has to work as a “recipe book” for plant staff. So Thai stays on the plant floor, and the English version is the one that counts. CBAM is the one place we know of where English is not a courtesy to an international audience but a written legal requirement. We set out the English rule in detail here →

Why a TGO carbon footprint does not get you there

Many Thai manufacturers already hold a TGO carbon footprint. It is useful groundwork, but it is not a CBAM report, and saying otherwise costs credibility the moment a verifier opens the file. The Commission’s operator guidance says CBAM “has differences to other methods for calculating product carbon footprints such as the ‘GHG Protocol’ or ISO14067.”

What transfers is the data infrastructure: metering, fuel and electricity records, a documented boundary, people who know where the numbers live. That is a real head start. The output must be rebuilt to CBAM’s installation-level rules. How TGO CFO work is structured →

The honest case for using default values

We would be doing our readers a disservice if we presented verified actual data as compulsory. It is not.

Default values are lawful and need no verification. They carry a mark-up of 10% for 2026, 20% for 2027 and 30% from 2028. The legal obligation sits with the EU declarant, not with the Thai operator. Importers bringing in under 50 tonnes a year are outside the regime altogether. Registering your installation is voluntary. And for Thailand as a whole the exposure is small: CBAM steel and aluminium were about 1.4% of everything the EU imported from Thailand in the first half of 2026.

So the real decision is commercial, and it turns on your carbon intensity. The charge applies to embedded emissions above a share of the EU benchmark, not to all of them. Defaults are not cheap for Thai bolts, though. The Commission’s default value for Thai carbon-steel threaded screws and bolts (CN 7318 15) is 2.408 tCO₂e per tonne, tied to the scrap-and-electric-furnace route, whose benchmark is only 0.066. Add the 10% mark-up, deduct 97.5% of that benchmark, and multiply by the published 2026 certificate prices. That comes to roughly €195 per tonne of bolts, about 12% of their average 2025 customs value. That is our illustrative arithmetic, not a quote, and it rises as the mark-up climbs. A plant that runs cleaner than the default value can save its customer real money with verified data. A plant that runs dirtier may be better off on defaults. Nobody can tell you which you are until your installation-level figure exists.

Brussels votes, Bangkok drafts its own CBAM

Two things move this month. In Brussels, the European Parliament’s procedure file lists 15 September 2026 for the plenary vote on its position on extending CBAM to downstream goods. The Commission proposed adding 180 steel- and aluminium-intensive products from 1 January 2028. It says they average 79% metal content and 94% are industrial supply-chain goods such as mountings, cylinders and industrial radiators. The Council agreed its position on 12 June, so talks between the institutions follow the vote. The product list may still change, and no official estimate of the Thai goods affected has been published.

In Bangkok, the Department of Climate Change and Environment reported its 17th weekly session explaining the draft Climate Change Act. It went through the emissions-trading chapter section by section with the SEC and the Stock Exchange of Thailand, and said the next session would take up the draft Act’s own cross-border carbon price adjustment chapter, a Thai CBAM. The Act is not law. But the direction is clear: the same installation-level, verified data that EU customers ask for is what the Thai state is drafting its own mechanism around. We track both processes here →

For SET-listed exporters there is a third reader. FTSE Russell scores listed companies from public disclosure only, with no questionnaire, and Thai is not among the key research languages its ESG FAQ names. Your English carbon figures now travel two roads: the CBAM report an EU verifier signs, and the public disclosure a rater reads. Under SEC Notification TorJor. 44/2556 clause 38, an English edition must say substantively the same as the Thai. Keeping one set of numbers, in both languages, is the control. How TGO carbon data flows into disclosure →

What a Thai exporter should decide before year-end

CBAM’s first full verification cycle will be decided in the next eleven months, mostly by people who never read a Thai document. The exporters who come through it well will have made one decision early: which numbers they stand behind, and in which language they are written down. ISO 17100 technical translation for carbon documents → · Why Thai CBAM tonnage doubled →

Sources: European Commission, news of 24 Aug 2026 on guidance for CBAM verifiers and accreditation bodies; Guidance on CBAM verification and accreditation (Aug 2026), §§4.1, 4.9, 4.15 and 9.2.1; CBAM verification and CBAM legislation-and-guidance pages; Guidance No. 2 for non-EU operators (14 Aug 2026); Commission Implementing Regulation (EU) 2025/2547, Arts 5(6) and 10(4); CBAM certificate price page (Q1 €75.36, Q2 €75.28); Commission default values file based on Implementing Regulation (EU) 2026/1740 (Thailand sheet) and CBAM benchmarks file based on Implementing Regulation (EU) 2025/2620; EFDA, CBAM cost calculation in 2026; Commission press release of 17 Dec 2025 on COM(2025) 989; Commission news of 12 Jun 2026 on the Council agreement; European Parliament Legislative Observatory, procedure 2025/0419(COD); Department of Climate Change and Environment, week-17 briefing on the draft Climate Change Act (dcce.go.th/28931); SEC Notification TorJor. 44/2556; FTSE Russell ESG Scores and Indices FAQ v1.5. Tonnage and trade shares are Othello analysis of Eurostat Comext dataset DS-045409 (EU-27 imports from Thailand, CBAM-scope CN headings, January–June 2025 and 2026). The first-visit reading of the site-visit conditions is our interpretation.