The EU’s Carbon Border Adjustment Mechanism (CBAM) is approaching its first mandatory verification cycle, placing greater emphasis on whether accredited auditors can assess the industrial processes behind reported emissions. For steelmakers, aluminium producers and multinational manufacturers, the ability to demonstrate sector-specific engineering expertise could become a key factor when selecting a verification provider.
The accreditation of the first CBAM verification bodies has established the foundations of a new assurance market. However, accreditation alone does not demonstrate how effectively an organisation can examine the operating characteristics of blast furnaces, electric arc furnaces, aluminium smelters or complex chemical installations.
In September 2026, Greece’s Hellenic Accreditation System extended EmiCert’s accreditation to all 11 CBAM activity groups, providing an early example of broad-sector coverage. Subsequent accreditations in Italy and Sweden have further expanded the emerging market.
European requirements call for verification bodies to demonstrate appropriate competence and assign qualified personnel to individual engagements. The commercial question is whether providers can translate those formal requirements into reliable assessments of specific industrial installations.
For EU importers, the distinction matters because the quality of verification can affect the credibility of emissions data used to support CBAM declarations and commercial decisions.
Steel audits demand knowledge of production processes
An integrated steelworks encompasses interconnected operations, from raw-material preparation and coke production to ironmaking, steel conversion, fuel-gas recovery and downstream manufacturing. Assessing its embedded emissions requires an understanding of how carbon moves through these processes and how emissions are attributed to different products.
At installations using blast furnaces and basic oxygen furnaces, verification teams need to examine reducing agents, coke consumption, process gases, carbon balances and relevant precursor materials. Electric arc furnace operations present a different set of technical considerations, including scrap and other metallic inputs, electrode consumption, injected carbon, auxiliary fuels and production yields.
Auditors must be able to identify inconsistencies between reported emissions and the facility’s operating data. For example, unusually low reported emissions alongside substantial consumption of carbon-intensive process materials may warrant further technical examination.
Relevant evidence can include production records, inventory movements, laboratory results, process-control data and material balances. These records help establish whether reported figures reflect actual plant operations.
The assessment becomes more complex when finished steel products incorporate semi-finished materials or other CBAM precursors produced at separate installations. Where actual precursor emissions are used under the applicable rules, the supporting evidence must correspond to the relevant producer, reporting period and activity.
A report can appear internally consistent while remaining unreliable if the verifier has not adequately examined the origin, quantities and emissions treatment of the materials used.
Aluminium verification requires different expertise
Aluminium production presents a distinct set of technical challenges. Primary aluminium is produced through electrolysis, with direct emissions associated with carbon-anode consumption and perfluorocarbon emissions. Secondary production involves recycled feedstock, remelting, refining and the associated consumption of fuels.
Further complexity arises in downstream manufacturing, where material classification, the use of unwrought aluminium and the allocation of emissions to covered products must be addressed correctly.
Experience in steel verification does not automatically establish competence in these processes, just as expertise in aluminium production does not necessarily equip an auditor to assess steelmaking.
Verification organisations serving multiple CBAM sectors must therefore assemble teams with the appropriate technical capabilities while maintaining consistent procedures and independence.
EU rules allow technical experts to support verification teams, but those specialists operate under the direction and responsibility of the verification body. External expertise can strengthen an assessment; it cannot replace the organisation’s own obligation to maintain adequate competence and control the verification process.
The 5% materiality threshold requires careful interpretation
The regulatory framework establishes a 5% materiality threshold for specific embedded emissions and specific embedded free allocation at the relevant product level. The threshold forms part of the verification framework, but it should not be treated as permission to overlook every discrepancy below that level.
Auditors must consider the nature of an error, its combined effects and whether it signals a wider weakness in monitoring or reporting. A relatively small discrepancy involving a high-volume precursor, for example, could expose a broader problem with data management or the underlying methodology.
Unexplained differences between laboratory measurements and production records may likewise require investigation before their full financial implications are known.
Effective verification consequently depends on more than checking calculations supplied by an installation operator. It requires professional scepticism, appropriate risk assessment and the ability to recognise inconsistencies in industrial evidence.
The EU framework requires reasonable assurance, with independent review before a verification conclusion is issued. Physical site visits are also part of the process, subject to the regulatory conditions under which virtual visits or waivers may be permitted.
Technical capability could differentiate verification providers
As the CBAM verification market develops, established assurance groups, specialist engineering firms and accredited environmental auditors will compete for industrial assignments. Broad accreditation may open access to several sectors, but the ability to deploy appropriately qualified teams could prove more important when handling technically demanding installations.
Large importers may increasingly seek evidence of sector-specific experience, including relevant site inspections, engineering qualifications and familiarity with emissions methodologies for different production routes.
Providers with access to metallurgical engineers, process specialists and experienced emissions auditors may be better equipped to undertake complex assignments. Organisations relying mainly on general carbon-accounting resources could face greater dependence on external specialists, additional costs and more demanding quality-control requirements.
The choice of verifier also matters to producers seeking to substantiate actual emissions that differ materially from the relevant default values. A weak verification process may leave a producer unable to support the emissions figures it wishes to report. Conversely, approval of understated figures can create subsequent compliance exposure and disputes with commercial partners.
For importers, reliable verification is therefore both a regulatory safeguard and a factor in assessing the credibility of suppliers’ emissions information.
The first CBAM accreditations show that the institutional framework for verification is taking shape, but they do not establish the quality of every subsequent engagement. As auditors move from accreditation documentation to operating steelworks and aluminium smelters, demonstrable industrial expertise—not accreditation alone—is likely to become a key measure of professional credibility.
