The EU’s Carbon Border Adjustment Mechanism (CBAM) is moving toward its first mandatory verification cycle, with attention on whether accredited auditors can assess the industrial processes behind reported emissions. The issue is relevant for steelmakers, aluminium producers and multinational manufacturers selecting verification providers.
Accreditation of the first CBAM verification bodies has helped establish an assurance market. However, accreditation does not by itself show how well 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. Further accreditations in Italy and Sweden have expanded the emerging verification market beyond its initial coverage.
European rules require verification bodies to demonstrate appropriate competence and assign qualified personnel to individual engagements. The commercial question is whether providers can translate those requirements into reliable assessments of specific industrial installations used for emissions reporting.
For EU importers, the distinction matters because verification quality can influence the credibility of emissions data supporting CBAM declarations and related commercial decisions. This links the verification process to how reported figures are used in compliance and purchasing contexts.
Steelworks verification relies on process-specific evidence
An integrated steelworks includes interconnected operations spanning raw-material preparation and coke production, followed by ironmaking, steel conversion, fuel-gas recovery and downstream manufacturing. Embedded emissions assessment depends on understanding how carbon flows through these processes and how emissions are attributed to different products.
At sites 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 require a different technical focus, including scrap and other metallic inputs, electrode consumption, injected carbon, auxiliary fuels and production yields.
Auditors are expected to detect inconsistencies between reported emissions and facility operating data. For instance, unusually low reported emissions alongside substantial consumption of carbon-intensive process materials may require additional technical examination.
Evidence used in these checks can include production records, inventory movements, laboratory results, process-control data and material balances. These records are used to determine whether reported figures reflect actual plant operations during the reporting period.
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 applicable rules, supporting evidence must match the relevant producer, reporting period and activity.
A report may be internally consistent while still being unreliable if the verifier does not adequately examine the origin, quantities and emissions treatment of materials used in production. This includes reviewing how precursor inputs are sourced and how their emissions are handled in calculations.
Aluminium verification covers electrolysis, recycling and allocation
Aluminium production involves distinct technical challenges for verification teams. Primary aluminium is produced through electrolysis, with direct emissions linked to carbon-anode consumption and perfluorocarbon emissions.
Secondary aluminium production uses recycled feedstock and involves remelting and refining alongside associated fuel consumption. Verification therefore needs coverage of both primary electrolysis-related emissions drivers and secondary processing inputs.
Downstream manufacturing adds further requirements related to material classification, use of unwrought aluminium and allocation of emissions to covered products. These steps affect how emissions are attributed within CBAM reporting for aluminium-related activities.
Experience in steel verification does not automatically establish competence for aluminium processes. Similarly, expertise in aluminium production does not necessarily equip an auditor to assess steelmaking operations under CBAM verification requirements.
Organisations providing verification across multiple CBAM sectors are expected to assemble teams with appropriate technical capabilities while maintaining consistent procedures and independence across engagements. This includes ensuring that sector-specific engineering knowledge is available for each assignment type.
EU rules also allow technical experts to support verification teams under the direction and responsibility of the verification body. External specialists can strengthen an assessment but cannot replace the organisation’s responsibility for maintaining adequate competence and controlling the verification process.
Materiality threshold shapes how discrepancies are assessed
The regulatory framework sets a 5% materiality threshold for specific embedded emissions and specific embedded free allocation at the relevant product level. The threshold is part of the verification framework but is not intended as permission to ignore every discrepancy below that level.
Auditors are required to consider the nature of an error, its combined effects and whether it indicates a broader weakness in monitoring or reporting. A relatively small discrepancy involving a high-volume precursor could point to wider problems with data management or underlying methodology.
Unexplained differences between laboratory measurements and production records may also require investigation before their full financial implications are known. This approach links technical consistency checks with downstream effects on reporting outcomes.
Effective verification depends on more than checking calculations supplied by an installation operator. It requires professional scepticism, appropriate risk assessment and the ability to recognise inconsistencies across industrial evidence sources used for CBAM reporting.
Assurance approach includes independent review and site visits
The EU framework requires reasonable assurance, including independent review before issuing a verification conclusion. Physical site visits form part of the process as well, subject to regulatory conditions under which virtual visits or waivers may be permitted.
As the CBAM verification market develops, established assurance groups, specialist engineering firms and accredited environmental auditors compete for industrial assignments. Broad accreditation may allow coverage across several sectors, but deploying appropriately qualified teams can be more important for technically demanding installations.
Large importers may seek evidence of sector-specific experience such as relevant site inspections, engineering qualifications and familiarity with emissions methodologies for different production routes. This demand reflects how technical capability connects to engagement outcomes across industrial facilities.
Providers with access to metallurgical engineers, process specialists and experienced emissions auditors may be better positioned for complex assignments. Organisations relying mainly on general carbon-accounting resources could face greater dependence on external specialists alongside additional costs and more demanding quality-control requirements.
Verifier selection affects support for reported default values
The choice of verifier can affect producers seeking to substantiate actual emissions that differ materially from relevant default values. A weak verification process may leave a producer unable to support the emissions figures it intends to report under CBAM rules.
If understated figures are approved through a deficient process, it can create compliance exposure and disputes with commercial partners. For importers, reliable verification functions both as a regulatory safeguard and as an input into assessing suppliers’ credibility regarding emissions information.
The first CBAM accreditations indicate that institutional arrangements for verification are taking shape. They do not establish the quality of every later engagement as auditors move from accreditation documentation toward operating steelworks and aluminium smelters covered by CBAM activity groups.