What is CBAM? An end-to-end guide for exporters into the EU

CBAM — the Carbon Border Adjustment Mechanism — puts a carbon cost on greenhouse gas emissions released while producing certain goods imported into the EU, equivalent to what an EU producer pays. The stated aim is to stop carbon leakage. An EU cement producer pays a per-tonne carbon cost under the ETS, while importing the same product from a country with no carbon price used to be cheaper. CBAM closes that gap at the border.

Which goods are covered?

CBAM defines its scope by CN code; the “sector” label is not what binds legally, the customs tariff heading on the list is. The initial scope covers six groups, chosen because they are carbon-intensive, trade-exposed and receive free allocation inside the ETS.

• Cement — clinker, Portland cement, aluminous cement
• Iron and steel — pig iron, flat and long products, tubes, certain steel articles
• Aluminium — primary and secondary aluminium, profiles, sheet, foil
• Fertilisers — ammonia, nitric acid, urea, blended fertilisers
• Electricity — cross-border electricity imports
• Hydrogen — imported hydrogen

Extending scope to “downstream” goods — finished products that contain CBAM materials — is under discussion. Fasteners, structural steelwork and aluminium joinery sit at the centre of that debate. Even if you are out of scope today, if steel or aluminium is your main input this belongs in your medium-term plan.

Timeline: transitional and definitive periods

The mechanism has two phases. In the transitional period that began on 1 October 2023 there was no financial liability; the importer merely filed a quarterly CBAM report declaring embedded emissions. In the definitive period the declaration becomes annual, the importer must be registered as an authorised CBAM declarant, and CBAM certificates are surrendered against the declared emissions. The report turns into a cost line.

The critical shift for an exporter is this: in the transitional period a report with gaps or default figures was acceptable, whereas in the definitive period the actual emissions data behind the declaration is expected to be verified by an accredited verifier. Unverified data means falling back to default values — and defaults are almost always worse than your real performance.

Who carries the obligation — exporter or importer?

The legally liable party is the EU importer. They buy the certificates, file the declaration and pay the penalty. In practice, though, the data sits with you. The importer will ask you for installation-level production route, fuel consumption, electricity source and precursor emissions. A supplier who cannot provide the data pushes their importer’s cost up to default values — a direct competitive disadvantage. So CBAM is legally the importer’s problem and commercially the exporter’s.

Five things to do now

• Match your CN codes against the list — scope is per product, not per company
• Define installation boundaries: which production processes belong to which good, where the meters sit
• Split fuel, electricity and process emissions by production route
• Request precursor emissions data from your own upstream suppliers
• Put data collection on an annual, auditable, traceable footing

CBAM is not the same thing as LCA

The embedded emissions you calculate for CBAM are not an LCA output. CBAM measures specific processes up to the installation gate, with its own system boundary and a greenhouse-gas-only focus; transport, use and end-of-life are out of scope. An EPD, by contrast, covers fifteen-plus impact categories and modules from A1 through D. Both draw on the same raw data but do not produce the same number — confusing the two is the most common CBAM mistake.

The good news is that the data layer is shared. Model energy, fuel and material flows properly at installation level once, and the same inventory produces both the CBAM embedded emissions report and EN 15804+A2 result tables. The clca platform keeps the inventory in one place; CBAM’s narrow system boundary and the EPD’s wider module structure are reported separately from the same data.