CBAM verifier registration is open: the two-stage Registry procedure, and why working access waits until September 30

CBAM verifier registration opened on September 1, 2026, and the European Commission published the instruction manual for it four days earlier: a 40-page access procedure, released August 28, that splits Registry access into two stages handled by two different authorities. The technical half runs through EU Access and is reviewed by the Commission. The business half, the application to become a Registered CBAM Accredited Verifier, is decided by the national competent authority (NCA) of the country where the verifier holds its accreditation.

The opening is a milestone with an asterisk. Registration is now possible, but working Registry access for accredited verifiers follows no earlier than September 30, 2026, and the market the window serves still contains no accredited verifier anywhere in the EU. The Commission's own accreditation snapshot, refreshed September 1, counts 24 national accreditation bodies offering CBAM accreditation and records not one completed accreditation among them.

How the two-stage Registry access procedure works

Registry access for accredited verifiers runs in two stages: a technical-user access request through EU Access, reviewed by the European Commission, followed by a registration application in the O3CI portal, decided by the NCA of the country of accreditation. The procedure document (version 1.00, dated August 25 and published August 28) states the split in its own disclaimer: "EU access is a first step, to request the technical user access. This step is a prerequisite to request access to the CBAM registry." The second step "will be managed by the National Competent Authority of the country of accreditation."

In practice, an accredited verification body works through five steps, listed below.

1. Create an EU Login account with two-factor authentication for the person who will manage access.
2. Submit a technical-user access request through the EU Access system, with the supporting evidence, including accreditation documents, bundled into a single PDF upload.
3. Wait for the Commission's decision: the procedure says "an administrator at the European Commission will review it" and warns that the process "may take several days after submission."
4. Enter the O3CI portal at cbam.ec.europa.eu/o3cinstallation, open the Accredited Entity Information section, and submit the registration request to the NCA of the accreditation country.
5. Receive the NCA's decision, which turns an accredited entity into a Registered CBAM Accredited Verifier able to operate in the Registry.

O3CI stands for Operators of Third Countries Installations, and the name reveals the design: verifiers get access through the same portal that non-EU producers use, because that is where the two sides meet. Inside it, an operator communicates its emissions report to the verifier, the verifier produces the verification report, and the operator then shares the verified figures with the authorised declarant who imports the goods. Both EU and non-EU companies can follow the procedure, provided their accreditation comes from an EU member state's national accreditation body. How accounts, logins, and roles fit together across the wider system is mapped in our CBAM Registry guide.

Which document carries which date

Five verifier publications landed between August 24 and September 1, 2026, and pinning each to its real date matters because summaries circulating in the market have already begun to merge them. The table below lists what the Commission actually published, and when.

References to a "141-page verification guidance published August 28" conflate the first and third rows: the 141-page guidance is the August 24 document, whose practical consequences for installations, including the rule that every verified plant needs a site visit in its first verification year, this site has already covered. What August 28 added is narrower and more operational: the access mechanics that make the September 1 opening usable.

The two-month clock and the September 30 access floor

An accredited verifier must register in the CBAM Registry within two months of receiving its accreditation, but not before September 1, 2026, and working Registry access follows no earlier than September 30, 2026. The Commission stated the deadline plainly in its August 24 announcement: "CBAM verifiers must register in the CBAM Registry within two months of receiving their CBAM accreditation, but not before 1 September 2026." The September 30 floor is older news; the July webinar follow-up already put registry access for accredited verifiers no earlier than that date, as covered when verifier registry registration was first scheduled for September. The new procedure document adds the mechanics but no new dates, and the gap between the two Septembers is where the processing happens: several days of Commission review on the technical request, then the NCA's assessment of the registration application.

The application itself is documentation-heavy. Under Article 10a(2) of the CBAM Registry Act (Implementing Regulation (EU) 2024/3210), a verifier registers with:

• its name and unique accreditation identification
• every accreditation scope relevant for CBAM
• its country of establishment
• the effective date and expiry date of the CBAM-relevant accreditation certificate
• any administrative measures imposed on it
• a copy of the accreditation certificate

Registration is not an administrative nicety but the on-switch for the entire service. The August 24 guidance is explicit that "it is not possible for the verifier to issue a verification report without access to the CBAM Registry." The first reports follow a fixed date, set out in the Commission's August 24 announcement: "Starting from January 2027, they will issue verification reports in the CBAM Registry, thus allowing importers to use actual verified emissions to complete their CBAM declaration."

24 accreditation bodies offering, zero verifiers accredited

The September 1 state-of-play counts 24 national accreditation bodies that have agreed to provide CBAM accreditation and 14 ready to accept applications, and it records no completed accreditation anywhere. The Commission's verification page still describes the first accreditations in the future tense: "The first CBAM verifiers are expected to receive CBAM accreditation around September 2026."

The refresh does show the third-country channel widening. Seven accreditation bodies have agreed to accredit third-country applicants, and five, in France (COFRAC), Italy (Accredia), the Netherlands (RvA), Poland (PCA), and Sweden (Swedac), already accept those applications. RvA additionally reports an agreement with Türkiye's TURKAK, and Swedac with Ukraine's NAAU. Three bodies put dates on their remaining gaps: Portugal's IPAC expects to accept applications in September 2026, Slovakia's SNAS in October, and Slovenia's SA in November. Our accredited CBAM verifiers tracker follows the state of play country by country and will list the first firms the day a NAB announces them.

For importers, the September 1 opening changes the timetable without changing the shortage. Certificates of accreditation must still be granted, registrations processed, and site visits scheduled before any verified 2026 figure exists, which is why finding a CBAM verifier early remains the binding constraint for anyone planning to declare actual values instead of marked-up defaults.

What happens next

Three dates now frame the verifier pipeline: working Registry access from September 30, 2026 at the earliest, the first in-Registry verification reports from January 2027, and the first annual declaration on September 30, 2027. Each accreditation granted this autumn starts its own two-month registration clock, so the register of verifiers will fill in waves through late 2026. The opening also lands in the busiest CBAM month of the definitive phase so far, one of eight dated events on the September 2026 calendar. When the first accreditation is announced, the question for compliance teams shifts from whether verifiers exist to which one can reach their supplier's installation in time.