European Commission publishes CBAM verification and accreditation guidance

On 24 August 2026 the European Commission published its guidance document on verification and accreditation under the Carbon Border Adjustment Mechanism (CBAM). The 141-page document is addressed to verifiers and national accreditation bodies, and explains the application of Implementing Regulation (EU) 2025/2546 on verification principles, Delegated Regulation (EU) 2025/2551 on accreditation, and Implementing Regulation (EU) 2025/2547 on calculation methods. By its own disclaimer the guidance is not legally binding and of an explanatory nature; it creates no new obligations. You can download the full guidance here.

According to the guidance, there is no fixed legal deadline for verifying a CBAM emissions report. Since the reporting period is the calendar year, verification cannot be completed before January of the following year. Because authorised declarants must submit their annual CBAM declaration by 30 September, the guidance expects verification reports to be delivered by mid-August at the latest. Installations producing complex goods have to wait for the verification reports of the installations producing their precursors; installations producing simple goods are therefore advised to complete their verifications as early in the year as possible. Where precursor reports do not arrive in time, the relevant data is substituted with the default values published by the Commission.

Other rules highlighted in the document: the materiality level is set, for each good identified by its CN code, at 5 % of the total specific embedded emissions per tonne and 5 % of the specific embedded free allocation; for all other parameters the verifier’s expert judgement applies. The site visit is physical by default; where the conditions are met it can be replaced by a virtual visit every second year, or waived entirely every third year — but the two exceptions cannot be applied cumulatively. Installations carrying out only processes excluded from the system boundaries also remain subject to verification and a site visit where actual values are to be used. In addition, a monitoring plan that has not been deemed adequate by an accredited verifier counts as a scope limitation and leads to a negative verification statement.

For precursor stocks, the default rule is that the precursor is deemed produced in the same year as the complex good. A claim of an earlier production year requires evidence; the guidance lists, among acceptable evidence, a delivery note or an invoice specifying the delivery date, a written confirmation from the producing installation, a steel mill certificate carrying the heat number, an analysis certificate for aluminium, and physical markings attached to the product. Verifiers disregard production-year claims dating back to before 2026; all stocks carried over into 2026 from earlier years are treated as produced in 2026. For precursors produced within the EU, no production-year evidence is required and the embedded emissions are taken as zero.

The guidance has also been added to our CBAM Guidance Documents archive.