The definitive rules for the EU CBAM are in force since January 1, 2026. Just in time, the EU Commission adopted the regulatory pieces defining their implementation. 13 EU acts define how CBAM works from 2026 onward covering 3 application areas for administration & customs, purchasing, and finance departments.
(Last updated 05/01/2026)
Finalizing the CBAM legislation
Just a few weeks before the EU’s Carbon Border Adjustment Mechanism (CBAM) enters its definitive phase, the key pieces of the regulatory puzzle are finally out.
Starting January 1, importing companies of CBAM goods will face new costs – tied to the purchase of CBAM certificates. These costs will reflect the carbon prices paid by EU producers under the EU’s Emissions Trading System (ETS).
The legal foundation for CBAM is Regulation (EU) 2023/956. It was originally published in May 2023. A wide range of amendments were published in Regulation 2025/2083 in October 2025 to simplify and strengthen the mechanism.
This core regulation empowers the European Commission (EC) to adopt implementing and delegated acts to define the detailed rules for CBAM from 2026.
On December 17, 2025 the EC published the provisional texts of the missing pieces for the definitive phase. The official texts were published a few days later in the EU Journal.
The package consists of:
- Delegated regulation for the accreditation of CBAM verifiers
- Implementing regulations for verification principles, calculation of embedded emissions, free allocation adjustments, and certificate prices.
- Amendments to implementing regulations for the rules for authorization of CBAM Declarants and CBAM Registry.
In addition, the EC published its review of the CBAM application including impacts and recommendations for next steps and proposals for additional measures to strengthen CBAM.
Amending regulatory CBAM foundations
One key objective is to strengthen CBAM to reduce the risks of carbon leakage and to protect the competitiveness of European companies. As announced earlier, the EC laid out proposals to expand the CBAM scope and to set-up a decarbonization fund.
The Decarbonisation Fund proposal (2025/990) would support energy-intensive industries at high carbon leakage risk. The temporary fund links financial aid to concrete decarbonisation investments.
Another proposal (2025/989) would amend the CBAM core regulation 2023/956. It would expand the scope of CBAM to additional goods made of iron & steel and aluminum further down metallic value chain. It also includes anti-circumvention measures, and simplified rules for emissions attribution.
These proposals now have to go through the EU’s trilogue process – as did earlier amendments to the regulation 2023/956 to simplify CBAM and ease compliance. They were first proposed by the EC as part of its Omnibus package in February 2025.
After a deal was reached in June, the adopted texts were published on October 17. Key rules start to apply from January 1, 2026. They also required changes to implementing rules.
EU acts to detail CBAM rules
The EC has now published the detailed rules for how CBAM will work from 2026. Overall, 13 acts consisting of delegated regulations (DR) and implementing regulations (IR) set the rules for CBAM implementation from 2026 onwards.
1. CBAM authorization and custom rules
From 2026, CBAM goods may only be imported into the EU by authorized CBAM declarants. Importers must have submitted an application for authorization by March 31, 2026 to continue importing CBAM goods.
IR 2025/486 was already published in March 2025 with applications opening March 31, 2025. Rules were amened in IR 2025/2549 to reflect the new timeline and rules for provisional imports.
Authorizations are run via the CBAM Registry, for which the rules have been published in IR 2024/3219 amended and corrected by IR 2025/2550. The Registry serves as central platform for declarants and authorities.
IR 2025/2619 sets out the rules for how customs authorities must communicate information under the CBAM framework to the Commission and competent authorities for compliance checks. This information covers EORI or alternative identifiers, importer details, and relevant customs documents.
IR 2025/2210 defines additional rules for CBAM goods entering the exclusive economic zone of Member States.
2. CBAM emissions and their verification
Already during the transition period, importers had to report actual emissions from the production of CBAM goods – governed by IR 2023/1773. So far, there was no formal mechanism to ensure that reported data meets CBAM methods.
From 2026, only verified emissions data will be accepted — confirmed by accredited CBAM verifiers, who will be responsible for:
- Reviewing emission monitoring and calculation methods
- Conducting on-site inspections of production facilities
- Issuing verification reports to the producers
DR 2025/2551 sets the conditions for accreditation of CBAM verifiers by EU recognized accreditation bodies across EU member states. It ensures harmonized verification standards and consistent application of accreditation rules.
IR 2025/2546 establishes the principles and requirements for verifying declared embedded emissions under CBAM. It details verifier obligations, verification methodologies, and conditions for ensuring accuracy and consistency in emissions reporting.
IR 2025/2547 sets out the methods for calculating embedded emissions in CBAM goods by installation operators as producers. It covers rules for determining actual emissions at installation level ensuring consistency and transparency in emissions reporting.
If no verified data is available, importers must use default values set for the country of origin — plus a cost-increasing mark-up. Both elements are published in IR 2025/2621.
3. CBAM certificates and their calculation
Importers must purchase and surrender CBAM certificates for the embedded emissions in their goods imported from January 1, 2026 onwards. Annually, they will also need to declare the number of certificates to be surrendered. An upcoming IR will set the rules for this CBAM declaration.
The number of certificates will be adjusted for:
- The level of free allowances granted to EU producers
- Carbon prices already paid in the country of origin
IR 2025/2620 defines the method for calculating the adjustment applied to CBAM certificates to account for free allocation under the EU ETS. This adjustment makes importers to only surrender certificates for emissions above a benchmark, based on EU production standards and adjusted with a CBAM factor.
An upcoming IR will define how to convert carbon prices paid abroad into a number of CBAM certificates — including how to assess actual payments vs. compensation. This act is also expected to define which carbon prices can be credited for in CBAM.
IR 2025/2548 establishes how the price to be paid for CBAM certificates is calculated and published. It is aligned with the average auction price of EU ETS allowances. It is set at quarterly base for imports in 2026 and weekly from 2027 onwards.
An upcoming DR will set the rules for buying, selling, and returning certificates. Only authorized declarants can purchase CBAM certificates, which will be traded through a Central EU Platform. Start date is February 2027.
Little preparation time for far reaching rules
With these implementation details coming out shortly before the start of the definitive period, importers have little time to get prepared for these rules and fully assess their full business implications.
Preparation is needed across three key areas:
- Clarify organizational CBAM responsibilities and processes: Designate CBAM leads, define roles across departments, and establish customs and compliance processes;
- Build-up CBAM data: Monitor purchasing and import data across all relevant CN codes and secure reliable emissions data from suppliers;
- Prepare for financial management: Factor-in CBAM costs in procurement and sales, align finance teams to manage CBAM certificate purchasing, budgeting, and hedging against carbon price volatility.
Until now, CBAM has mainly been an administrative reporting task. But from now on, it will become a strategic and financial issue. The implementation challenges ahead will require close collaboration between finance, procurement, and customs teams.
Sources and further information:
- European Commission: CBAM Legislation and Guidance
- EU: Regulation establishing CBAM (2023/956)
