Short answer
The EU ETS and CBAM use a similar chain—measure, report, verify where required, and surrender carbon units—but regulate different actors.
Under the EU ETS, the legal account sits with the emitter: the operator of a stationary installation, the aircraft operator, or the shipping company. That actor monitors under an approved plan, reports annual emissions, arranges accredited verification and surrenders EU allowances. Buying allowances is a market transaction needed when the account lacks enough units; it is not a separate emissions tax.
Under the definitive CBAM regime, which applies to imports from 1 January 2026, the account normally sits with the authorised CBAM declarant: an EU-established importer acting directly or an indirect customs representative acting in that capacity. The declarant reports imported quantities and embedded emissions, secures verification when it uses actual emissions, buys CBAM certificates from the common platform and surrenders them. A third-country installation operator supplies data and an accredited verifier checks it, but neither thereby becomes responsible for the declarant's annual CBAM obligation.
Certificate pricing and the adjustment for free ETS allocation connect the systems, but EU allowances and CBAM certificates are not interchangeable.
EU ETS: the regulated emitter owns the compliance cycle
Stationary installations
An operator may not carry out a covered Annex I activity without a greenhouse-gas emissions permit. The permit identifies the installation and operator, requires an approved monitoring plan and includes the obligation to surrender allowances.
The operator must monitor under Commission Implementing Regulation 2018/2066, maintain supporting records, submit its annual emissions report to the competent authority and engage an accredited verifier. The verifier applies Regulation 2018/2067, assesses the report and monitoring system, and issues a verification opinion. It does not prepare the operator's data or assume the operator's liability.
The final registry act remains the operator's. Article 12(3) of the ETS Directive requires Member States to ensure that, by 30 September each year:
“the operator of each installation surrenders a number of allowances that is equal to the total emissions from that installation during the preceding calendar year”. —
Free allocation reduces how many allowances must be bought, not the surrender number for verified emissions. The operator acquires any shortfall from an auction or market counterparty; surrender cancels units in the Union Registry.
Aircraft operators
For covered aviation, the aircraft operator submits an emissions monitoring plan to its administering Member State, monitors covered flights, reports annual emissions and obtains verification. The operator then surrenders allowances equal to the prior year's verified covered emissions by the same 30 September deadline.
The aircraft operator is the person operating the aircraft when the activity occurs, or the owner if that person is unknown or unidentified. Free aviation allocation was phased out for ordinary compliance by 2026, although targeted fuel support and scope derogations remain. CORSIA offsetting and EU ETS surrender must be checked separately.
The Court upheld aviation's inclusion in Air Transport Association of America, C-366/10, but today's route scope and derogations come from the current Directive.
Shipping companies
For maritime transport, the shipping company is the shipowner or the organisation or person that has assumed operation and the International Safety Management Code duties. It monitors and reports ship-level data under Regulation 2015/757 and submits verified aggregated emissions at company level for ETS purposes.
A fuel buyer, charterer or commercial operator may contractually reimburse the carbon cost, but the Directive leaves the shipping company responsible for surrender and compliance.
Maritime surrender was phased in: 40% of covered verified 2024 emissions, 70% for 2025 and 100% for 2026 onward. Ordinarily, coverage is 100% for voyages between Member-State ports and emissions in those ports, and 50% for voyages between a Member-State and third-country port. Ship, gas and voyage exceptions remain relevant.
ETS verification is a gate, not a transfer of liability
The authority administers compliance, the verifier independently tests the report, and the regulated actor remains responsible for reporting and surrender.
In Billerud Karlsborg, C-203/12, the Court held that holding enough allowances was not surrender:
operators could not avoid the penalty “even where they hold a sufficient number of allowances on that date”. —
The judgment concerned the former 30 April deadline; the current deadline is 30 September. Under Article 16, an indexed per-tonne penalty applies and payment does not erase outstanding surrender. Repeated shipping non-compliance can lead to expulsion or detention.
CBAM: the authorised declarant owns the import account
CBAM initially covers listed cement, iron and steel, aluminium, fertilisers, electricity and hydrogen. For the first four sectors, an importer is exempt for a calendar year if aggregate net imports do not exceed the 50-tonne single mass-based threshold. Electricity and hydrogen are excluded from that exemption. Once exceeded, duties cover all relevant imports that year, including quantities below 50 tonnes.
An EU-established importer expecting to exceed the threshold must obtain authorised-declarant status. An indirect customs representative must obtain that status before acting in that role; for a non-EU-established importer, the representative must be the authorised declarant. The representative then assumes the importer's CBAM duties for those goods.
Delegating the technical submission of a declaration does not delegate responsibility. The authorised declarant remains liable.
Reporting and verification in the definitive regime
The transitional quarterly-reporting period ended on 31 December 2025. For 2026 imports, the first definitive annual declaration is due on 30 September 2027. The amended regulation states:
“each authorised CBAM declarant shall use the CBAM registry … to submit a CBAM declaration for the preceding calendar year.” —
The declaration reports quantities, embedded emissions and the surrender number after any permitted third-country carbon-price deduction and EU ETS free-allocation adjustment. Records must support official review.
Embedded emissions may use actual emissions or applicable default values. Actual emissions require a CBAM-accredited verifier. Regulations 2025/2546 and 2025/2547 govern verification and calculation; Regulations 2025/2621 and 2025/2620 govern default values and the free-allocation adjustment. The third-country operator supplies data, the verifier checks it, and the declarant remains responsible.
Certificates, payment and surrender
Member States begin selling CBAM certificates on 1 February 2027, including for 2026 imports. Their 2026 price uses the quarterly average of EU ETS auction closing prices for the quarter of importation; from 2027 the ordinary calculation uses weekly averages.
By 30 September each year—first in 2027 for 2026 imports—the authorised declarant must have and surrender through the CBAM registry the required number of certificates. From 2027 it must also maintain, at each quarter-end, certificates corresponding to at least 50% of embedded emissions in goods imported since the year's start, subject to the regulation's calculation choices and free-allocation adjustment.
CBAM certificates are bought and, within limits, repurchased through the platform; they are not freely traded EU allowances. A carbon price effectively paid abroad can reduce surrender only when the evidence requirements are met.
Failure to surrender triggers a per-certificate penalty aligned with the ETS excess-emissions penalty. For an authorised declarant, paying it does not remove the outstanding surrender obligation. An unauthorised importer exceeding the threshold faces a separate penalty architecture.
Conclusion
Both regimes make verified emissions the basis of a registry surrender, but they attach that duty to different legal actors. EU ETS follows the emitting installation, aircraft operator or shipping company. CBAM follows the authorised declarant responsible for the import.
Verification supports the account; it does not own it. Contractual reimbursement, outsourced reporting or data supplied by a third-country producer can redistribute work or economic cost, but the statute determines who reports and surrenders. For 2026, the decisive CBAM dates are the start of the definitive regime on 1 January 2026, certificate sales from 1 February 2027, and the first annual declaration and surrender on 30 September 2027.
Sources
This article provides general legal information, not advice for a specific matter. Laws, facts and procedural deadlines may change the result. Follow the linked primary sources and obtain local advice before acting.