Methodology
How CBAMWorks calculates
Specific embedded emissions per CN code, using the EU method. Every number ties back to a bill, a meter reading or a production log at the supplier's installation.
The pipeline
- Activity data — fuels (quantity × NCV × emission factor), electricity (where in scope), production tonnes per product.
- Process emissions — direct non-fuel emissions from the production process (e.g. decarbonation).
- Installation total — summed direct emissions, plus indirect emissions for sectors where they count.
- Attribution — allocated across products using the EU rules.
- Per tonne per CN code — the specific embedded emissions, compared to the default plus mark-up.
Rules the engine applies
- steelAluDirectOnly
- For iron, steel and aluminium, only direct emissions count. The exception: indirect emissions of sintered-ore precursors carry into steel goods. For cement and fertilisers, direct and indirect emissions both count. Source
- defaultMarkup
- +10 % in 2026, +20 % in 2027, +30 % from 2028 Source
- verification
- Actual values must be verified by an EU-accredited verifier. A physical site visit is required in the first verified year. Source
Checked on 2026-10-18
Reference data versioning
Default values, NCVs, grid factors and goods categories come from official Commission tables, loaded into versioned reference data. Changes are logged on the rule tracker.