CBAM reporting: the complete guide for 2026

Step-by-step handbook for CBAM reporting in 2026: deadlines, data requirements, calculations, and tools for an error-free declaration.

Pillar context

The Carbon Border Adjustment Mechanism (CBAM) enters its definitive phase in 2026. After the transitional period of quarterly reporting without financial obligations, importers now face actual certificate costs, stricter data requirements, and more stringent audit demands. This guide provides a complete overview of the CBAM reporting process in 2026, from preparation to submission.

What changes in 2026?

The transition from the transitional phase to the definitive phase brings fundamental changes. During the transitional period (2023-2025), CBAM reporting was primarily an information obligation. Importers had to submit quarterly reports on the embedded emissions of imported goods, but there were no financial consequences attached to this reporting.

From 2026, this changes drastically. Importers must purchase CBAM certificates corresponding to the embedded emissions of their imports. The price of these certificates is linked to the EU ETS carbon price. Importers who hold insufficient certificates face penalties. Additionally, data quality requirements are tightened and default values are less readily accepted.

Product scope

CBAM applies to the import of goods in the following categories: iron and steel, aluminium, cement, fertilisers, electricity, and hydrogen. Within these categories, specific products are defined using Combined Nomenclature (CN) codes. It is essential to carefully check your product portfolio against the CBAM product list, as the scope in the definitive phase differs from the transitional period.

Financial impact

The financial impact of CBAM depends on import volume, embedded emissions per product, and the EU ETS carbon price. At a carbon price of 80 euros per tonne of CO2 and an average embedded emission of 2 tonnes of CO2 per tonne of steel, certificate costs amount to 160 euros per tonne of imported steel. For an importer with an annual volume of 10,000 tonnes of steel, this means an additional cost of 1.6 million euros.

The reporting process step by step

Step 1: Becoming an authorised CBAM declarant

Before you can import CBAM goods, you must register as an authorised CBAM declarant with the competent national authority. In the Netherlands, this is the Dutch Emissions Authority (NEa), in Germany the Deutsche Emissionshandelsstelle (DEHSt), in Belgium the regional environmental agencies, and in France the Ministry of Ecological Transition.

The registration process includes applying for CBAM declarant status, providing company information and EORI number, designating a responsible person for CBAM reporting, and confirming your ability to use the CBAM reporting system.

Step 2: Determining embedded emissions

Determining embedded emissions is the core of CBAM reporting. A distinction is made between direct emissions and indirect emissions.

Direct emissions are the emissions released during the production process itself. For steel, this includes, for example, the combustion of coal in the blast furnace and the chemical reactions during iron ore reduction.

Indirect emissions are the emissions related to the generation of electricity used in the production process. Whether and to what extent indirect emissions must be included varies by product category and is determined by the CBAM regulation.

Data collection from producers

The most accurate approach is obtaining actual emissions data from the producer. This requires direct communication with the producer about their emission intensity per product, insight into their measurement methods and verification standards, documentation of the production location and production process used, and information about any carbon prices already paid in the country of production.

Default values

When actual emissions data is not available, you can use default values. The European Commission publishes default values per product category and per country of origin. The use of default values is subject to stricter conditions in the definitive phase and will in many cases lead to higher calculated emissions than with actual data.

Step 3: Purchasing CBAM certificates

Based on the calculated embedded emissions, you purchase CBAM certificates. Certificates are sold through the national CBAM registry at a price determined by the weighted average of EU ETS auction prices from the preceding week.

Purchase timing. You are not required to purchase all certificates in advance. A minimum number of certificates must be held per quarter, based on your average imports. The definitive settlement takes place annually.

Surplus certificates. Unused certificates can be sold back to the national registry, albeit at a lower price than the purchase price.

Step 4: Correction for carbon price in country of origin

If a carbon price has been paid in the country where the goods were produced, you can apply a correction to the number of CBAM certificates required. This requires demonstrating that a carbon price was actually paid, documenting the amount of the carbon price paid, and proving that the carbon price relates to the specific production of the imported goods.

Step 5: Submitting the CBAM declaration

The annual CBAM declaration must be submitted by 31 May of the year following the reporting year. The declaration contains the total quantity of imported CBAM goods per product category, the total embedded emissions per product category, the number of CBAM certificates used, any corrections for carbon prices paid in the country of origin, and the verification statement from an accredited verifier.

Step 6: Verification

The CBAM declaration must be verified by an accredited verifier. The verification includes checking the emissions data and calculation methods used, assessing the documentation and audit trail, verifying the corrections for carbon prices in the country of origin, and issuing a verification statement.

Data quality and documentation

Data hierarchy

The CBAM regulation applies a clear hierarchy for the quality of emissions data. Preference is given to actual, verified emissions data from the producer. When this is not available, an estimated value based on the best available data is accepted. As a last resort, the default values published by the European Commission apply.

Documentation requirements

For every CBAM declaration, you must have the following documentation available: import documents with CN codes, quantities, and country of origin, emissions data from producers with measurement method and verification status, PSR calculations if relevant for origin determination, evidence of carbon prices paid in the country of origin, communications with producers about emissions data, and the verification statement.

Archiving

All CBAM-related documentation must be retained for at least 5 years after the year to which the declaration relates. This includes not only the declaration itself but also all underlying source data and communications.

Common mistakes

Mistake 1: Starting data collection too late

Collecting actual emissions data from producers is time-consuming. Producers in third countries are not always familiar with CBAM requirements and need time to compile the requested data. Start contacting your producers at least 6 months before the reporting deadline.

Mistake 2: Insufficient documentation of default values

When using default values, document why actual data is not available and what efforts you have made to obtain it. An auditor will want to see that you have made a reasonable effort.

Mistake 3: Not substantiating carbon price correction

The correction for carbon prices paid in the country of origin can yield significant savings but must be thoroughly substantiated. Insufficient documentation leads to rejection of the correction.

Mistake 4: Incorrectly determining scope

Not all products within the named categories fall under CBAM. Carefully check the specific CN codes and consult the European Commission guidelines or your national authority if in doubt.

Mistake 5: Overlooking indirect emissions

For certain product categories, indirect emissions must also be reported. Check per product category whether indirect emissions are in scope and ensure you collect the necessary data.

Deadlines and 2026 calendar

The key deadlines for CBAM reporting in 2026 are as follows. Per quarter, you must hold the minimum number of CBAM certificates. The annual CBAM declaration for 2025 must be submitted by 31 May 2026. Verification must be completed before the submission date. The return of surplus certificates can be requested until 30 June.

Quarterly rhythm

Although the definitive settlement takes place annually, there is a quarterly obligation to hold at minimum the average number of certificates corresponding to your imports in the preceding quarter. This prevents importers from deferring all certificate purchases until the last moment.

CBAM and preferential origin

CBAM reporting and preferential origin are closely intertwined. The origin of goods determines not only whether preferential tariffs apply but also affects the CBAM calculation. Country-specific emissions default values differ by country of origin. The carbon price correction depends on the country where the goods were produced. The production location determines which emission factors apply.

Organisations that manage preferential origin and CBAM within the same workflow prevent inconsistencies and reduce duplication of effort.

Integration with existing compliance processes

Synergy with supplier declarations

The CBAM data collection process shares significant overlap with the supplier declaration process for preferential origin. In both cases, you request information from producers about their production process. An integrated approach where you request both origin data and emissions data from the same contact is more efficient and promotes data quality.

Synergy with supply chain due diligence

The Corporate Sustainability Due Diligence Directive (CSDDD) requires companies to map their supply chain and identify risks. The data you collect for CBAM about production locations and processes is directly usable for CSDDD compliance.

Central compliance platform

A central platform combining preferential origin, CBAM reporting, and supply chain due diligence offers a single source of truth, reduces the number of touchpoints with producers, ensures consistency across different reporting streams, and strengthens the audit trail.

Tools and automation

What to automate

The following components of the CBAM reporting process lend themselves to automation: identifying CBAM-liable import transactions based on CN codes, calculating embedded emissions based on available data, monitoring certificate positions and minimum requirements per quarter, generating the annual CBAM declaration, and managing communications with producers about emissions data.

Selection criteria for CBAM software

When selecting CBAM software, consider support for all CBAM product categories and CN codes, integration with your ERP system and customs software, support for the data hierarchy (actual data, estimates, default values), certificate management including purchase, position monitoring, and return, reporting functionality conforming to official templates, and audit trail and documentation management.

Outlook: CBAM beyond 2026

The European Commission has announced that the CBAM product scope will be expanded in future years. Sectors not currently covered by CBAM but potentially to be added include organic chemicals, polymers, and certain finished products of steel and aluminium.

Organisations that invest now in a scalable CBAM reporting process are prepared for this expansion without major adjustments.

Conclusion

CBAM reporting in 2026 is more complex and consequential than during the transitional period. The combination of financial obligations, stricter data requirements, and verification demands makes a structured approach indispensable.

The key to successful CBAM compliance lies in early preparation, systematic data collection, and integration with existing compliance processes. Organisations that approach CBAM not as an isolated obligation but as part of a broader compliance strategy realise the greatest efficiency gains.

Next step

Request the CBAM reporting guide for the complete handbook with reporting templates, a deadline calendar, and an implementation checklist.

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Related definitions

  • CBAM: CBAM is the European mechanism linking emissions-related reporting and settlement to imported goods.
  • BOM: A BOM is the bill of materials: the structured composition of a product.
  • Audit trail: An audit trail records who did what, based on which source data, and with what decision logic.