How CBAM verification works for non-EU plants, and where accreditation stands

For a steel mill, aluminium smelter or fertiliser plant outside the EU that sells into the bloc, the EU's carbon border adjustment mechanism (CBAM) now turns on a practical question: who will verify its emissions, and when. Verification is how a non-EU producer's actual emissions data, rather than default values, reach the declarations its EU customers file. The European Commission published new guidance and registry procedures for verifiers on 28 September, and on 7 October a table showing which national accreditation bodies are ready to accredit verifiers based outside the EU. This explainer sets out how the system works and where it stands, from the Commission's verification page and the documents linked from it.

How verification works

CBAM verification applies at the level of the installation where CBAM goods are produced. The non-EU operator monitors and calculates embedded emissions under the CBAM methodology and gives the information to an accredited verifier. The verifier reviews the monitoring approach, the calculations and the evidence, visits the installation and issues one verification report per installation. The operator transmits its emissions data and the verification report through the CBAM Registry, and EU declarants retrieve the verified emissions there to complete their CBAM declarations, according to the Commission.

Verifiers provide reasonable assurance that the calculation of embedded emissions is correct, and are overseen by national accreditation bodies in EU countries, the page says. Verification reports used by importers may also be reviewed by the Commission and by national competent authorities, which may impose penalties on declarants. The rules are set out in Commission Implementing Regulation (EU) 2025/2546 on verification principles, Delegated Regulation (EU) 2025/2551 on accreditation and verification, and Implementing Regulation (EU) 2025/2547 on emissions calculation methods.

Only national accreditation bodies in EU countries, or in EEA countries once the CBAM Regulation is incorporated into the EEA Agreement, can grant CBAM accreditation. A verification company established in the EU must, as a rule, apply to the body in its own country. Companies established outside the EU may apply to any national accreditation body that offers the service, according to the verification page. Applicants must show technical competence in the relevant sectors, independence and impartiality, and consistent and reliable verification approaches.

The timeline and where accreditation stands

The timeline runs as follows, according to its verification page:

• January 2026: importers apply for CBAM authorisation and start importing; operators start monitoring and calculating embedded emissions.
• April 2026: national accreditation bodies begin CBAM accreditation.
• September 2026: accredited verifiers can register in the CBAM Registry, and the first verifications, with documentation reviews and site visits, start.
• January 2027: accredited verifiers can issue the first verification reports, and operators can share them with declarants.
• February 2027: declarants can buy CBAM certificates.
• September 2027: declarants finalise their CBAM declarations for 2026.

The page says the first verifiers were expected to be accredited around September 2026 and that the list of accredited verifiers will be published there. Verifiers must register in the CBAM Registry, and the Commission's 28 September notice describes the procedure for verifiers to obtain registry access from 1 September 2026, along with user guides and training videos for the registry's O3CI portal, including on managing collaboration requests with operators of third-country installations.

The Commission's state-of-play table, dated 7 October, lists the accreditation bodies of the 27 member states and Norway. Its totals show that 24 bodies have agreed to provide CBAM accreditation, 18 have agreed to accredit applicants from outside the EU, 7 are ready to accept applications and 7 are already accepting applications from third-country applicants.

The seven bodies already accepting third-country applications are in France (COFRAC), Greece (ESYD), Italy (Accredia), the Netherlands (RvA), Poland (PCA), Slovakia (SNAS) and Sweden (Swedac), the table shows. Two entries carry notes relevant to large exporting countries: the Dutch body's line refers to an agreement with TURKAK, Türkiye's accreditation agency, and the Swedish body's to an agreement with NAAU, Ukraine's national accreditation agency. The table does not describe what those agreements cover.

Several bodies have not agreed to provide CBAM accreditation, including those of Cyprus, Estonia, Ireland and Malta, and others, such as Croatia, the Czech Republic and Hungary, provide it but have not agreed to accredit third-country applicants. Romania's and Slovenia's entries mark October and November 2026 respectively against the question of accrediting third-country applicants, according to the table.

The guidance on verification and accreditation, dated 24 August, focuses mainly on verifiers who will verify reports from operators of non-EU installations producing CBAM goods imported from 1 January 2026, and explains the rules for the bodies that accredit and supervise them, the Commission's notice says. The verification page lists Spanish, French, Arabic, Portuguese, Chinese, Japanese, Korean, Ukrainian, Vietnamese, Indonesian and Turkish versions as coming soon.

For producers, the sequence is fixed by the timeline: monitoring has run since January, verification visits could start in September, and reports can be issued from January 2027, ahead of declarations for 2026 due in September 2027. With seven accreditation bodies accepting third-country applications as of 7 October, the pool of verifiers able to work for non-EU installations is still forming. Producers that want their EU customers to use verified actual emissions will need a verifier in place within that window.