The CBAM Registry and the O3CI Operator Portal: How Non-EU Producers Share Emissions Data

What the CBAM Registry does

The CBAM Registry is the operating infrastructure of the mechanism and runs alongside the EU's other customs systems. It serves four user groups:

• Authorised CBAM declarants — authorisation applications, the annual CBAM declaration, certificate transactions
• Third-country operators — installation details, emissions data, verification reports
• Accredited verifiers — verification activity
• Member state competent authorities and the Commission — oversight

Data flows between customs administrations and the Commission run through the same infrastructure, so a consignment's customs status and a declarant's authorisation status are matched automatically.

The problem the operator module solves

The most common practical complaint of the transitional period was repetition. A steel producer selling to ten EU customers filled in ten templates, often in ten formats with ten different question sets. Consistency was difficult to maintain and commercially sensitive information circulated more widely than necessary.

The O3CI module — the portal for operators of third-country installations — centralises this. The operator enters company and installation details, production route, annual emissions data and the verification report once, then decides which EU customers may access it. Declarants can then populate their declarations directly from that data.

Two benefits follow. Administrative burden falls. More importantly, the data has a single source, which removes the risk of inconsistency — two customers holding different figures for the same installation and period is a serious problem at verification.

Preparing to register

Access runs through the EU's central authentication infrastructure, so registration is less a technical exercise than a documentation one. The points to settle before registering:

• Legal entity versus installation. Registration is meaningful at installation level, not company level. Groups with several production sites register each separately.
• Installation identity. Address, coordinates and any national registry identifiers.
• Production route. Default values are set by route, so this is a critical field — the difference between electric arc furnace and integrated steelmaking starts here.
• Covered goods produced. Listed by CN code.
• Emissions data and verification report. By reporting period.
• Authorised person. Who enters data and exercises the sharing permission.

The Commission published a detailed manual for the installation operator and accredited verifier portal on 27 August 2026, covering screen flows and field definitions.

The commercial side of sharing

The sharing model gives control to the producer: the operator decides who sees the data. That raises two questions.

The first is how much to disclose to whom. The rules allow a summary report for commercially sensitive information — the verifier sees the full dataset while what reaches the customer can be a summary. This distinction should be settled before registering.

The second is that the data becomes a commercial instrument. For an installation performing below the country average, the portal is the most direct way to make that visible. Installations that share nothing are represented by the country default value plus mark-up — so not appearing in the portal means accepting a marked-up country average in place of your own performance.

Registration is likely to become a condition

Registration is not mandatory today; a producer can still send data directly to its customer. The Commission's anti-circumvention proposals, however, include a requirement that third-country operators register in the CBAM Registry in order for actual emissions data to be used. The same proposals would allow additional conditions on actual emissions claims, additional evidence on the installation and date of production, and a standard CBAM declaration format.

The direction of travel suggests registration will become a de facto precondition. We cover the proposals in CBAM anti-circumvention rules.

How registration relates to verification

The portal is also where verification is recorded. Verifiers began registering on 1 September 2026, and the first verification reports are expected in January 2027. Because the operator's data and the verifier's report are matched in the system, the sequence matters: emissions data uploaded before verification is complete remains unfinished. We cover the process in CBAM verification and accredited verifiers.

Frequently asked questions

Is registration charged for?

No fee is foreseen for portal registration. The cost sits in the emissions calculation and verification that fill it.

Our customer does not use the portal. Does that matter?

Data can still be sent directly. With several customers, the portal is the safer route for consistency.

Is commercially sensitive data protected?

Sharing permission rests with the operator, and a summary report can be produced for sensitive information. The full dataset is seen by the verifier and competent authorities.

We export through a trader. Who registers?

The operator of the installation where the goods were produced. An intermediary cannot be the source of emissions data.

Sources

• European Commission — CBAM Registry
• European Commission — CBAM definitive regime

We work on preparing installation and emissions data for the portal and defining the scope of what is shared, under our CBAM accounting and reporting service. You can contact us with your questions.