From 01/01/2026 CBAM stops being a reporting exercise and becomes a real invoice: EU importers of Vietnamese steel and aluminum must buy CBAM certificates matching the emissions embedded in the goods, priced off the EU carbon market. The Vietnamese FDI exporter does not surrender certificates, but pays through the selling price — EU buyers will deduct CBAM costs from any supplier unable to provide low, credible actual emissions data. The cost model must therefore be built on the Vietnamese side, from Vietnamese plant data.
How CBAM is charged per tonne and who buys certificates
Under Regulation (EU) 2023/956 the mechanism runs as follows: the authorised EU importer declares imported volumes and embedded emissions computed by the EU methodology — for steel and aluminum covering direct production emissions and a defined share of indirect emissions by product group; during the year the importer buys CBAM certificates at a price set by the weekly average EU ETS auction price; at period end it surrenders certificates equal to declared embedded emissions, with a deduction for a carbon price demonstrably paid in the country of origin. The per-tonne charge is thus embedded emissions times certificate price, adjusted by two moving parts: the remaining EU ETS free allocation for the equivalent sector (phasing down on a schedule, pushing the effective obligation up each year) and any carbon price paid at production.
Where emissions data comes from: default values are the expensive trap
Companies choose between two data routes: EU default values — set deliberately unfavourably to push firms toward real data — or building an actual plant measurement system to the CBAM methodology: product system boundaries, fuel and electricity consumption by process step, grid emission factors, and lot-level traceability files. For steel, emissions vary widely by furnace technology, so default values can multiply cost several times over a well-run plant reporting actuals. The measurement and verification build cost — methodology advice, metering, an accredited verifier — typically pays back within the first definitive CBAM year for a high-volume exporter.
Cutting CBAM cost legitimately
Three lawful levers: cut real embedded emissions — furnace energy efficiency, higher scrap ratios in steel and aluminum smelting, certified green electricity for the indirect component under the methodology; optimise product scope — separate product lines and HS codes cleanly so one data gap does not drag a whole shipment onto default values; and negotiate commercially — CBAM cost-sharing clauses with the EU importer, data-for-price commitments, and a dated switch plan to verified actual data. The unlawful and dangerous lever is under-declaring emissions or routing through a third country: CBAM carries its own anti-circumvention rules, with back-charges and penalties in the EU beyond negotiation.
Conclusion and Next Steps
CBAM turns carbon data into a cost component on par with raw materials: steel and aluminum exporters who can measure real, low emissions keep their margin; exporters who let buyers apply default values pay for their own data laziness on every tonne. The cost model must be built once, updated against ETS prices and the free-allocation phase-down — and built now.
Frequently Asked Questions
1. How is the CBAM cost per tonne calculated?
Embedded emissions of the import times the CBAM certificate price (the weekly average EU ETS price), adjusted for the sectors remaining free allocation and any carbon price proven paid in the country of origin.
2. Who must buy CBAM certificates?
The authorised EU importer, not the Vietnamese exporter. But the cost is pushed back through price negotiation, so a Vietnamese plant without actual emissions data is discounted by the unfavourable default values.
3. Where does CBAM emissions data come from?
Either EU default values, set unfavourably, or actual plant measurement to the CBAM methodology: fuel and power by process step, grid factors, lot traceability, verified by an accredited verifier.
4. How can CBAM cost be cut legitimately?
Real emission cuts via energy efficiency and scrap ratios, green power for the indirect part, clean product-line separation to avoid defaults, and cost-sharing plus data-for-price clauses with the EU importer.
This article has been quality-reviewed by the FLAW AI Legal Council