EU CBAM Q4 2026 Reporting: HS Chapter Coverage and Quarterly Filing Trigger Table

The EU Carbon Border Adjustment Mechanism entered its transitional phase October 1 2023 with the first quarterly reports due January 31 2024. As of Q4 2026, the transitional phase is in its final quarter and the definitive regime with financial adjustment starts January 1 2027.

This guide covers the exact HS chapter coverage of CBAM in its current form, the quarterly filing trigger threshold, the default emissions values available through the end of the transitional phase, and the mechanics of the financial adjustment starting 2027.

What triggers a CBAM filing obligation

Any importer bringing goods covered by CBAM Annex I into the EU customs territory during a calendar quarter must file a CBAM quarterly report by the end of the following month.

The de minimis threshold is 150 EUR per consignment. Consignments below 150 EUR are outside CBAM entirely. There is no annual aggregation, so multiple small consignments do not accumulate into a trigger obligation. However, most industrial imports of covered goods (iron/steel, aluminum, fertilizer, cement, hydrogen, electricity) far exceed 150 EUR per consignment.

The Q4 2026 report covers imports cleared October 1 through December 31 2026 and must be filed by January 31 2027 through the CBAM Transitional Registry portal.

The six covered sectors and CN chapter coverage

CBAM applies to six sectors defined in Annex I of the CBAM Regulation:

Iron and steel: CN chapter 72 in full (pig iron, ferro-alloys, primary steel, semi-finished and flat products), plus specified covered articles in CN chapter 73 (tubes, pipes, structures, tanks, screws, bolts). Not all of chapter 73 is covered. Verify each CN 8-digit code against the annex.

Aluminum: CN chapter 76 covered subheadings including unwrought aluminum (7601), aluminum bars/rods/profiles (7604), aluminum plates/sheets/strip (7606, 7607), aluminum foil (7607), and aluminum structures (7610).

Fertilizers: Specified CN chapter 31 headings including 2808.00 (nitric acid), 2814 (ammonia), 2834.21 (potassium nitrate), 3102 (nitrogen mineral or chemical fertilizers), 3105 (other mineral or chemical fertilizers).

Cement: CN chapter 25 covered subheadings 2507.00 (kaolin), 2523 (portland cement, aluminous cement, slag cement).

Hydrogen: CN chapter 28 subheading 2804.10 (hydrogen).

Electricity: CN chapter 27 subheading 2716.00 (electrical energy).

If any component of a niche product falls in one of these subheadings (a steel hardware kit inside a hobby product, an aluminum housing on an electronic device, a fertilizer additive in an agricultural formulation), the covered component triggers a CBAM filing obligation for the covered CN portion.

The transitional phase reporting requirements

From October 2023 through December 2026, importers of covered goods must file a quarterly CBAM report through the Transitional Registry. The report must include:

• Total quantity of each covered good imported, by CN code
• Country of origin
• Installation-level data on production facility (name, address, verified when possible)
• Total embedded direct emissions (Scope 1) in tonnes CO2-equivalent per tonne of good
• Total embedded indirect emissions (Scope 2 from electricity used in production) where applicable
• Any carbon price effectively paid in the country of production for the embedded emissions

Through the end of 2025, importers could use European Commission default emissions values without penalty. From January 2026, default values may only cover up to 20 percent of the total embedded emissions in a report. The rest must be actual data.

The financial adjustment starting January 2027

From January 1 2027, the definitive regime applies. Importers must:

• Register as an Authorised CBAM Declarant with their competent national authority
• Purchase CBAM certificates at a price linked to the weekly average EU ETS auction price (published on the Commission's CBAM portal)
• Surrender certificates annually by May 31 for the previous calendar year's imports, against verified embedded emissions

The certificate surrender obligation covers the difference between the verified embedded emissions of the imported good and any carbon price effectively paid in the country of production. If a Chinese steel article has 2 tonnes CO2 per tonne of steel and the effective China-side carbon price paid is zero, the importer surrenders certificates for all 2 tonnes at the weekly ETS price (running approximately 70 to 90 EUR per tonne CO2 in 2026).

For a 500 tonne shipment of Chinese steel articles with an embedded emissions intensity of 2 tCO2/t, the 2027 CBAM cost at 80 EUR per certificate is 80,000 EUR on top of MFN duty and any AD order already applicable.

Stacking with MFN duty and anti-dumping orders

CBAM does not replace or offset existing duty layers. A Chinese-origin steel article covered by an EU anti-dumping order at 25 percent plus an MFN duty of 2 percent will, from 2027, carry an additional CBAM charge on top. The three layers stack.

For importers of Chinese-origin covered goods, the effective landed cost in 2027 will be substantially higher than the 2026 transitional-phase cost. The EU Commission has published guidance on the definitive regime and the certificate purchase mechanics through the CBAM portal at taxation-customs.ec.europa.eu.

Practical checklist for Q4 2026 filers

Before January 31 2027, importers who cleared covered goods in October through December 2026 should:

1. Pull the list of all EU import entries by CN code for Q4 2026
2. Filter to CN codes in CBAM Annex I (iron/steel chapters 72 and covered 73, aluminum chapter 76, fertilizer covered 31, cement covered 25, hydrogen 2804.10, electricity 2716.00)
3. Request installation-level actual embedded emissions data from each supplier for the covered goods
4. Where actual data is unavailable, use default values but cap defaults at 20 percent of the total embedded emissions in the report
5. Log any effective carbon price paid in the country of production for the embedded emissions
6. File the Q4 2026 report through the CBAM Transitional Registry by January 31 2027
7. Register as an Authorised CBAM Declarant with the national competent authority ahead of the January 1 2027 definitive regime start