Verification and accredited verifiers

The verification obligation

Verification is a cornerstone of the CBAM system. Article 8 of Regulation 956/2023 requires that the embedded emissions declared in the annual CBAM declaration be verified by an accredited verifier in accordance with the principles defined in Annex VI and Implementing Regulation 2025/2546.

The verification covers:

• The accuracy of emissions data communicated by third-country installations
• The conformity of calculation methods with the requirements of Regulation 2025/2547
• The consistency between imported quantities and declared emissions
• The correct attribution of emissions to the relevant products
• The completeness of the system boundaries used in the calculation

Verification provides the assurance mechanism that prevents underreporting of emissions. Without it, importers could claim artificially low emissions to reduce their certificate obligations.

Who is subject to verification?

Every authorised CBAM declarant who uses actual emissions (Method 1 or 3 from chapter 4) must have those data verified. The sole exception: if the declarant uses exclusively the Commission's default values, verification is not required (but the cost in certificates is higher).

In practice, most operators with significant CBAM exposure will use actual emissions for at least some of their suppliers, making verification an annual obligation.

The verification process

Phase 1: Planning

The accredited verifier and the CBAM declarant agree on a verification plan covering:

• The scope of installations to be verified (which suppliers, which production sites)
• The products concerned and their CN codes
• The reporting period (calendar year)
• The calculation methods used by each installation (direct measurement, calculation, estimation)
• The documents and data to be provided (fuel purchase invoices, production records, electricity bills)
• The timeline for data submission and report delivery

Timing: Verification planning should begin in January of the year following the reporting year (year N+1), with data collection in January-March and the verification itself in March-April, to meet the 31 May declaration deadline.

Phase 2: Data evaluation

The verifier analyses:

1. System boundaries: are the boundaries of the installation correctly defined? Are all material and energy flows included? Are co-generation and heat recovery properly accounted for?
2. Combustion data: are the fuel quantities documented and consistent with purchase invoices? Are the emission factors appropriate for the fuel types used?
3. Process emissions: are the calculations compliant with the methods in Annex IV of Regulation 956/2023? For cement, is the clinker-to-cement ratio correctly applied? For aluminium, are anode effects properly quantified?
4. Electricity data: are the electricity consumption and emission factor documented (for sectors where indirect emissions are covered)? Is the source of the emission factor appropriate (grid average vs. contractual)?
5. Product attribution: are the total installation emissions correctly allocated among the different products? Is the allocation methodology (mass, energy, economic value) appropriate and consistently applied?
6. Precursor emissions: if the product uses CBAM precursors, are their embedded emissions correctly incorporated?

Phase 3: On-site verification (if necessary)

The verifier may conduct an on-site visit to the third-country installation if the data provided does not allow for reasonable assurance. In practice, remote verifications are often preferred for third-country installations, using:

• Video conferencing for interviews with plant management and technical staff
• Remote examination of measurement systems (photos, videos, calibration records)
• In-depth documentary analysis with screen-sharing
• Third-party site visits by local verification bodies (subcontracting arrangements)

When is on-site verification required? The verifier exercises professional judgement, but on-site visits are typically triggered when:

• Emissions data shows significant unexplained variations year-on-year
• The installation is new or has undergone major modifications
• Documentation gaps cannot be resolved remotely
• The installation's emissions represent a material proportion of the declarant's total CBAM exposure

Phase 4: Verification report

The verifier produces a verification report compliant with Annex VI of Regulation 956/2023, containing:

• The verification opinion: reasonable assurance (clean opinion) or limited assurance (qualified opinion)
• Findings on each installation and each product
• Any reservations or discrepancies identified, with their materiality assessment
• Recommendations for improvement of the installation's monitoring system
• The signature of the accredited verifier and the lead verifier

The report is attached to the annual CBAM declaration submitted in the CBAM registry.

Types of verification opinions:

• Unqualified opinion (reasonable assurance): the verifier is satisfied that the emissions data is free from material misstatement
• Qualified opinion: material misstatements were identified but are confined to specific areas; the rest of the data is reliable
• Adverse opinion: the emissions data is materially misstated to such an extent that it cannot be relied upon
• Disclaimer of opinion: the verifier was unable to obtain sufficient evidence to form an opinion

Accredited verifiers

Accreditation conditions

Regulation 2025/2551 defines the accreditation conditions for CBAM verifiers:

1. ISO 14065 accreditation: the verifier must be accredited under ISO 14065 (validation and verification bodies for greenhouse gases). This international standard ensures competence, consistency, and impartiality
2. Sectoral competence: the verifier must demonstrate expertise in the CBAM sectors (cement, steel, aluminium, fertilisers, electricity, hydrogen). Sectoral scopes are specified in the accreditation
3. Independence: the verifier must have no conflict of interest with the verified installation or the CBAM declarant. This includes financial relationships, consulting arrangements, or shared management
4. National accreditation: accreditation is issued by a national accreditation body (e.g. COFRAC in France, DAkkS in Germany, UKAS in the UK, ENAC in Spain, ACCREDIA in Italy)
5. Continuous professional development: verifiers must maintain their competence through regular training and audits by the accreditation body

Finding a verifier

• The European Commission maintains a list of accredited verifiers in the CBAM registry
• National accreditation bodies also publish their registers of accredited bodies
• Major verification firms with CBAM capability include: Bureau Veritas, SGS, TUV (Nord, Rheinland, SUD), DNV, EY, Deloitte, LRQA
• Specialised environmental verification firms may offer more competitive pricing for smaller portfolios

Verification cost

The cost of verification depends on:

• The number of installations to verify (each installation requires separate analysis)
• The complexity of production processes (a multi-product steel mill is more complex than a single-product cement plant)
• The geographic location of installations (access, language, timezone, travel requirements)
• The number of products and CN codes concerned
• The quality of the installation's monitoring and documentation systems

Cost range: EUR 3,000 to 15,000 per installation verified, depending on complexity.

Cost optimisation: Declarants importing from multiple installations operated by the same company may negotiate portfolio rates. Early engagement with the verifier (January) typically results in better pricing and scheduling.

Verification principles (Annex VI)

Annex VI of Regulation 956/2023 defines the guiding principles of verification.

Materiality

The verifier assesses whether inaccuracies, taken individually or collectively, are likely to influence the decisions of users. The materiality threshold is generally set at 5% of total emissions. Misstatements below this threshold are noted but do not trigger a qualified opinion.

Completeness

All relevant emission sources must be taken into account. No significant omission is acceptable. This includes auxiliary fuels, emergency generators, process emissions from all relevant chemical reactions, and (where applicable) indirect emissions from purchased electricity.

Consistency

Calculation methods must be applied consistently from one period to the next. Any change of method must be justified, documented, and its impact quantified. This ensures year-on-year comparability of emissions data.

Transparency

All assumptions, data, and calculations must be documented and traceable. The verifier must be able to reconstruct the emissions calculation from source documents (fuel invoices, production logs, electricity meter readings) to the final reported figure.

Interaction with the competent authority

Article 19 provides that the competent authority may carry out a review of the CBAM declaration and the verification report. If anomalies are detected:

• The authority may request supplementary information from the declarant
• It may impose a correction of the declaration, potentially requiring additional certificates
• It may apply penalties in case of inaccurate declaration (Article 26)
• It may refer the matter to the accreditation body if verifier performance is in question
• As a last resort, it may suspend or revoke the authorised CBAM declarant status

The competent authority has the power to conduct its own independent assessment of emissions data, including requesting direct access to installation records. Cooperation with the authority is an ongoing obligation of the authorised CBAM declarant.