CBAM verification requires exporters to show that reported emissions figures can be reproduced using production records, measurement data, and supporting documentation. The assessment focuses on whether an installation’s monitoring arrangements and calculation methods provide sufficient evidence for the emissions information submitted to EU customers.
The verification is carried out under a reasonable assurance approach aimed at ensuring an operator’s emissions report contains no material misstatements. Verifiers must obtain enough evidence to support their conclusions, while not being required to examine every individual transaction. A spreadsheet presentation alone cannot compensate for missing source records or for an inability to explain how reported figures were calculated.
Monitoring plan and evidence supporting emissions calculations
The installation’s monitoring plan is used as the starting point for the assessment. The verifier checks whether it follows the applicable methodology, including how production processes are defined and how relevant emissions sources and material inputs are treated. Operators also need to identify which records support individual calculations and confirm who maintains those records.
Production data, material consumption, and emissions inputs must align into a consistent account for the reporting year. Fuel invoices should correspond with consumption records, meter readings should match the relevant calculation periods, and product quantities should be reconcilable with production systems. Where precursor emissions are relevant, supporting information must relate to materials used in production rather than only quantities purchased.
Reconciliation of reporting-year records and handling discrepancies
Differences between records do not automatically indicate errors. Inventory changes, production losses, rejected products, yield variations, and changes in operating conditions can explain mismatches across documentation.
The issue arises when an operator cannot document those movements or reproduce the calculation. Verifiers are expected to follow the evidence trail without relying solely on explanations provided by individual employees.
On-site checks and traceability through source documents
A physical visit to the installation is required during the first reporting year subject to verification. Operators are therefore expected to prepare personnel responsible for measurement equipment, production data, procurement, and emissions calculations so they can explain procedures and demonstrate how the monitoring system works in practice.
One preparation approach is to select a reported emissions value and trace it backward through the calculation to the relevant source document, measurement, or transaction. A reverse check can also be performed by selecting an original record and showing how it contributes to the reported result. These checks can reveal omitted inputs, duplicated entries, and manual adjustments that have not been documented.
Evidence gaps, defaults, corrective steps, and verification files
Evidence gaps should be identified before the formal assessment begins. Operators are expected to follow the prescribed methodology rather than introduce unsupported estimates.
Where the rules allow default values, their use should be clearly recorded so that measured inputs, verified upstream emissions data, and defaults remain distinguishable within the calculation.
The verification process may require additional documentation, corrections, or improvements to reporting arrangements. An unsatisfactory outcome remains possible if material deficiencies are not resolved or if available evidence is insufficient to support an opinion. Companies should allow time for responses to requests instead of scheduling their first substantive review immediately before an EU customer deadline.
A controlled preparation file should include the monitoring plan, emissions report, indexed supporting records, calculation workbook, and a register of identified findings. These documents support demonstration of the basis for reported emissions figures but do not replace the independent verifier’s assessment.
Manufacturers with established production controls already have records that can support the process. They must connect those records to the applicable CBAM methodology and demonstrate that the resulting emissions figure can be reconstructed when requested by the verifier.