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 linked to reported emissions. The focus affects steelmakers, aluminium producers and multinational manufacturers selecting verification providers.
Accreditation for the first CBAM verification bodies has helped establish an assurance market. However, accreditation does not show how effectively an organisation can review 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 market.
European rules require verification bodies to demonstrate competence and assign qualified personnel to specific engagements. The key question for buyers is whether providers can convert these requirements into reliable assessments of particular industrial installations.
For EU importers, the verification standard can influence the credibility of emissions data used for CBAM declarations and related commercial decisions.
Steelworks verification relies on process-specific evidence
An integrated steelworks includes interconnected operations covering 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 steps and how emissions are attributed to different products.
At sites using blast furnaces and basic oxygen furnaces, verification teams are expected to examine reducing agents, coke consumption, process gases, carbon balances and relevant precursor materials. Electric arc furnace operations involve different technical considerations such as scrap and other metallic inputs, electrode consumption, injected carbon, auxiliary fuels and production yields.
Auditors need to detect inconsistencies between reported emissions and facility operating data. For instance, unusually low reported emissions alongside substantial use of carbon-intensive process materials may require additional technical examination.
Evidence used in assessments can include production records, inventory movements, laboratory results, process-control data and material balances. These records help determine whether reported figures reflect actual plant operations.
The assessment becomes more complex when finished steel products include 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 treatment of emissions for the materials used.
Aluminium assurance requires separate technical competence
Aluminium production involves distinct technical challenges compared with steelmaking. Primary aluminium is produced via electrolysis, with direct emissions linked to carbon-anode consumption and perfluorocarbon emissions.
Secondary aluminium production uses recycled feedstock and includes remelting and refining steps alongside fuel consumption. Downstream manufacturing adds further complexity through correct material classification, use of unwrought aluminium and allocation of emissions to covered products.
Experience in steel verification does not automatically translate into competence for these aluminium processes. Likewise, expertise in aluminium production does not necessarily equip an auditor to assess steelmaking operations.
Verification organisations covering multiple CBAM sectors are expected to assemble teams with appropriate technical capabilities while maintaining consistent procedures and independence. 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 verification organisation’s obligation to maintain adequate competence and control over 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 it.
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.
Differences between laboratory measurements and production records that remain unexplained may also need investigation before full financial implications are known. Effective verification therefore depends on more than checking calculations supplied by an installation operator.
The EU framework requires reasonable assurance, including independent review before a verification conclusion is issued. Physical site visits form part of the process as well, subject to regulatory conditions under which virtual visits or waivers may be permitted.
Provider capability may influence outcomes across sectors
As the CBAM verification market develops, established assurance groups, specialist engineering firms and accredited environmental auditors are expected to compete for industrial assignments. Broad accreditation can cover multiple sectors, but deploying appropriately qualified teams may be more important for technically demanding installations.
Larger importers may seek evidence of sector-specific experience such as 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 positioned for complex assignments.
Organisations relying mainly on general carbon-accounting resources could face greater dependence on external specialists, higher costs and more demanding quality-control requirements. The choice of verifier also affects producers seeking to substantiate actual emissions that differ materially from relevant default values.
A weak verification process may leave a producer unable to support reported emissions figures it intends to use. Conversely, approval of understated figures can create compliance exposure and disputes with commercial partners involving those emissions claims.
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 to assessments at operating steelworks and aluminium smelters.