Until today, the exposure calculator applied the flat phase-in share — 2.5% in 2026, 5% in 2027, 10% in 2028 — to all embedded emissions. That approximation appears in half the CBAM explainers on the internet, and it is only correct for a product that sits exactly at the EU ETS benchmark. Default values do not sit at the benchmark; they are set high on purpose. A reader called the calculator wrong, and on this point they were right. Fixed the same day, as follows.
The definitive-period rules in Implementing Reg (EU) 2025/2620 calculate the free allocation adjustment per good: certificates to surrender = embedded emissions − (CBAM factor × CBAM benchmark × tonnes), where the CBAM factor is 97.5% in 2026, 95% in 2027, and 90% in 2028, and the benchmark is the Column B value the regulation prescribes whenever default values are used (Annex, points 2 and 4). You deduct a slice of the benchmark, not of your own emissions — so everything a default value sits above the benchmark is payable from day one.
Worked example: flat-rolled steel from India (CN 7208, BF-BOF route). Default value with the 2026 markup: 4.708 tCO2e/t against a 1.37 benchmark. Payable: 4.708 − 0.975 × 1.37 = 3.372 tCO2e/t — about €270 per tonne at the current ETS price, or roughly €2.2 million on 8,000 tonnes. The flat 2.5% share said €9.4 per tonne. The correction is not subtle.
What changed under the hood: all 570 benchmark CN codes from the Reg 2025/2620 annex are now in the dataset, matched to every default value by CN code and production route (exact route per Annex pt 5.1, highest value where alloy grades leave it ambiguous, year variants applied — (1) covers 2026–27, (2) covers 2028–30). The certificate line now reconciles — certificates × ETS price equals the cost shown — and the “with verified actuals” savings are computed through the same formula, which makes them larger than before: the deduction stays fixed, so every tonne of CO2e cut from the emission value comes straight off the certificates. Electricity and the few goods without a benchmark get no deduction, as the regulation prescribes. The default values themselves, their markups (Reg 2025/2621), and the live ETS price were already correct and are unchanged.
Run your number again in the calculator — 2026 exposure is bigger than the flat-share estimates suggested, which also means reporting verified actuals is worth more than most importers think.