CBAM is the Carbon Border Adjustment Mechanism, set by Regulation (EU) 2023/956. It charges an EU importer for the carbon emitted when certain goods were made outside the EU. The importer pays by buying CBAM certificates, and one certificate covers one tonne of CO2 equivalent.
The charge exists because EU producers of the same goods already pay for their emissions under the EU Emissions Trading System (ETS). Without CBAM, steel made with coal outside the EU would carry no carbon cost at the border, and EU production would move to where carbon is free. The regulation calls that carbon leakage.
Sectors and CN codes in scope
6 sectors are in scope, listed by CN code in Annex I of the regulation:
| Sector | CN codes in scope |
|---|---|
| Iron and steel | 479 |
| Aluminium | 58 |
| Fertilisers | 27 |
| Cement | 6 |
| Electricity | 1 |
| Hydrogen | 1 |
Those are the 572 8-digit codes of the 2026 Combined Nomenclature that fall under Annex I. Iron and steel carries most of the list because it includes downstream goods. Screws, bolts, tubes, rails and steel structures are in scope, as well as the raw metal. The full list, with the default values for each code, is on the CBAM CN code list.
Who pays, and from when
CBAM ran a reporting-only transitional period from October 2023 to the end of 2025. The definitive regime started on 1 January 2026. From that date:
- An importer that brings in more than 50 tonnes of CBAM goods in a calendar year must be an authorised CBAM declarant. Electricity and hydrogen have no threshold.
- The declarant files one annual CBAM declaration for the year's imports, and surrenders certificates for the embedded emissions, by 30 September of the following year. The first deadline is 30 September 2027, for goods imported in 2026.
- Certificates go on sale on a common central platform from 1 February 2027. No certificates are held during 2026.
- From 2027, a declarant must hold certificates for at least 50% of the embedded emissions of the year's imports at the end of each quarter.
These dates come from Regulation (EU) 2025/2083, the simplification that amended the CBAM regulation in October 2025. It introduced the 50 t threshold, moved the declaration from 31 May to 30 September, and lowered the quarterly holding from 80% to 50%.
The obligation falls on the EU importer, not on the producer abroad. A producer outside the EU is still involved. Its buyer will ask for the actual emissions of its installation, because without them the buyer pays on default values, set high on purpose.
The cost calculation
The cost of one import line comes from 5 numbers:
- The mass, in tonnes.
- The embedded emissions per tonne, either actual verified data from the installation or the default value the Commission publishes for that CN code and country of origin.
- The mark-up on a default value: 10% in 2026, 20% in 2027, 30% from 2028. Fertilisers carry 1% in every year.
- The CBAM factor from Article 31. It is 2.5% in 2026 and rises to 100% in 2034, as free ETS allowances for EU producers are phased out.
- The certificate price, which the Commission publishes from EU ETS auction prices.
Certificates = mass × emissions per tonne × (1 + mark-up) × CBAM factor, rounded up. Cost = certificates × price. A carbon price already paid in the country of origin can be deducted.
Here is one real line: 1,000 tonnes of hot-rolled steel coil, CN 7208 39 00, from India, imported in 2026.
| Step | Value |
|---|---|
| Default value, India, CN 7208, route C | 4.28 tCO2e per tonne |
| With the 10% mark-up for 2026 | 4.708 tCO2e per tonne |
| Embedded emissions, 1,000 t | 4,708 tCO2e |
| CBAM factor 2026 | 2.5% |
| Emissions subject to CBAM | 117.7 tCO2e |
| Certificates, rounded up | 118 |
| Price, Q2 2026 | €75.28 |
| Cost | €8,883.04 |
The step-by-step method, with more examples, is in how to calculate CBAM cost.
The cost by import year
The same 1,000 tonnes from India costs €8,883 in 2026. Hold the certificate price at €75.28 and change only the year:
| Import year | Mark-up | CBAM factor | Certificates | Cost |
|---|---|---|---|---|
| 2026 | 10% | 2.5% | 118 | €8,883 |
| 2027 | 20% | 5% | 257 | €19,347 |
| 2028 | 30% | 10% | 557 | €41,931 |
| 2030 | 30% | 48.5% | 2,699 | €203,181 |
The factor doubles each year to 2028 and then climbs fast. By 2030 the same shipment costs 23 times its 2026 figure, before any move in the carbon price. That curve is the reason buyers now ask suppliers for actual emissions data: a supplier whose verified value sits below the default saves its buyer money every year. The cost chart draws this curve for any CN code and up to 4 countries.
Where the country of origin changes the answer
Default values differ by country. For the same 1,000 tonnes of CN 7208 39 00 in 2026:
| Origin | Default value with mark-up | Certificates | Cost |
|---|---|---|---|
| India | 4.708 | 118 | €8,883 |
| China | 3.506 | 88 | €6,625 |
| Ukraine | 2.731 | 69 | €5,194 |
| Türkiye | 2.671 | 67 | €5,044 |
| South Korea | 2.330 | 59 | €4,442 |
| United States | 1.540 | 39 | €2,936 |
The Commission publishes default values for 121 countries plus a rest-of-world value for every other origin. They were replaced in full on 31 July 2026. The changes are in CBAM default values 2026.
Your next steps as an importer
- Count your year's CBAM tonnage per importer entity. Below 50 t of the threshold goods, the obligation may not apply. See the 50-tonne threshold.
- Check the declarant status. Above 50 t, importing without authorisation is a breach.
- Price each of your lines on default values, then ask your largest suppliers for verified actual emissions where the default is high.
- Budget for the certificates at the quarterly price for 2026 imports, bought from February 2027 and surrendered by 30 September 2027.
Sources: Regulation (EU) 2023/956, as amended by Regulation (EU) 2025/2083. Default values from Regulation (EU) 2026/1740. Certificate price from the Commission's price page. Figures computed on 16 September 2026 from the CBAM Data dataset.