CBAM Definitive Period: The 2027 Declaration Deadline for Importers

The CBAM definitive period has applied since 1 January 2026. It applies to goods listed in Annex I to Regulation (EU) 2023/956 that originate in a third country and are imported into the Union, subject to the Regulation’s scope exclusions and exemptions, including the Article 2a de minimis exemption for the four mass-based sectors. Electricity and hydrogen are not covered by that de minimis exemption. On 14 August 2026 the European Commission published a set of ten guidance documents to tell those importers, and the non-EU installations that supply them, how the definitive regime actually works. The documents land at a useful moment: the first annual CBAM declaration and the first surrender of CBAM certificates, both covering goods imported during 2026, fall due on 30 September 2027.

That gap between the obligation starting in 2026 and the money changing hands in 2027 is a recurring source of early compliance uncertainty. Certificate sales open on 1 February 2027. The 2026 imports and the emissions basis ultimately used in the 2027 declaration therefore need to remain traceable. The Carbon Border Adjustment Mechanism was created by Regulation (EU) 2023/956, and it was reshaped for the compliance phase by the simplification package in Regulation (EU) 2025/2083. The guidance published in August 2026 sits on top of both, translating the legal text into the monitoring, calculation and declarant tasks a reporting team has to schedule.

Related reading: our guide to CBAM embedded and indirect emissions for importers.

Ten guidance documents, split four to six

The August 2026 series is made up of four general guidance documents and six sector-specific guides. The four general documents are Guidance No. 1 (an introduction to CBAM concepts, the compliance cycle, roles, milestones and exemptions), Guidance No. 2 (a quick guide for non-EU operators), Guidance No. 3 (calculation of embedded emissions) and Guidance No. 4 (calculation of the free allocation adjustment). The six sector guides, numbered 5a to 5f, cover cement, hydrogen, fertilisers, iron and steel, aluminium and electricity, each with worked examples for production processes, value chains and monitoring.

The audience matters as much as the content. The Commission aims the series at operators of installations outside the EU that produce CBAM goods, and at the authorised CBAM declarants and verifiers inside the compliance cycle. That split reflects how the regime is built: the authorised CBAM declarant carries the declaration and certificate-surrender obligations. Where actual emissions are used, the declarant relies on verified information relating to the relevant third-country installation; where actual values are not used, the applicable default values may be used instead.

Read as a package, the documents carry the Commission’s reading of Regulation (EU) 2023/956 as amended, and a guidance document cannot change a threshold or a deadline set in the regulation itself. Where a sector guide and Union law appear to diverge, Union law governs. The guidance is explanatory and non-binding; it was prepared by Commission services and is without prejudice to the Commission’s official position.

The dates that now govern the CBAM definitive period

Deadline pressure is the reason this topic cannot sit in a backlog. The operative calendar for the definitive period runs as follows:

• 1 October 2023 to 31 December 2025: the transitional period, quarterly reports of embedded emissions, no financial obligation and no certificates.
• 1 January 2026: the definitive regime applies. For CBAM imports not exempt under Article 2a, Article 4’s authorised-declarant rule applies, subject to Article 17(7a), which permits an importer or indirect customs representative that submitted an authorisation application by 31 March 2026 to continue importing provisionally until the competent authority decides.
• Calendar year 2026: monitoring and collection of embedded-emissions data for the goods imported during the year.
• 1 February 2027: sales of CBAM certificates begin on a common central platform.
• 30 September 2027: the first annual CBAM declaration for 2026 imports is due, and the first surrender of CBAM certificates falls due on the same date.
• 2026 to 2033: under current in-force Article 10a(1a) of the EU ETS Directive, the legal CBAM factor applied to remaining free allocation falls from 97.5% in 2026 to 14% in 2033; from 2034 no CBAM factor applies and, under current law, free allocation for the relevant CBAM goods has been phased out.

The simplification package moved two of these dates from where the original 2023 regulation had placed them. Certificate sales were pushed back from the start of 2026 to 1 February 2027, and the annual declaration deadline shifted from 31 May to 30 September. Anyone working from a 2024 project plan built on the original text is carrying the wrong dates.

Authorised declarant status is the gate to importing

Article 4 of Regulation (EU) 2023/956 provides that CBAM goods are imported only by an authorised CBAM declarant, subject to the Regulation’s exemptions and the provisional-import derogation in Article 17(7a). An importer or indirect customs representative that submitted an application by 31 March 2026 may continue importing provisionally until the competent authority decides. The authorisation procedure is governed by Implementing Regulation (EU) 2025/486, as amended and corrected by Implementing Regulation (EU) 2025/2549; applications are handled through the Authorisation Management Module of the CBAM registry.

For the annual CBAM declaration and certificate surrender, legal responsibility rests with the authorised CBAM declarant. Where the importer is established in an EU Member State, the importer is responsible unless an indirect customs representative acts as authorised CBAM declarant for the goods concerned; where the importer is not established in an EU Member State, the indirect customs representative must act as authorised CBAM declarant. A direct customs representative does not take over the importer’s CBAM responsibility. Article 5(4) provides a separate rule for electricity imported using explicit capacity allocation. Where actual emissions are used, data may be supplied by the relevant third-country operator, but legal responsibility for the CBAM declaration and certificate surrender remains with the authorised CBAM declarant.

Despite the deferred 2027 certificate dates, the 2026 calendar year carries substantive obligations. For imports subject to the authorisation requirement, the importer or relevant indirect customs representative must use the applicable authorised-declarant route; where an application was submitted by 31 March 2026, Article 17(7a) permits provisional import until the competent authority decides. Records for 2026 imports must also support whichever emissions method is used in the 2027 declaration, whether verified actual emissions or permitted default values.

The 50-tonne exemption and who it leaves in scope

Regulation (EU) 2025/2083 replaced the former EUR 150 per-consignment intrinsic-value exemption with the Article 2a single mass-based threshold. The current threshold is 50 tonnes of net mass, aggregated per importer and calendar year across the four mass-based sectors. An importer whose relevant imports do not exceed that threshold is exempt from the CBAM obligations but must declare the exemption in the relevant customs declaration. If the threshold is exceeded during the year, the CBAM obligations apply in respect of all emissions embedded in all covered goods imported in that calendar year.

The carve-out inside the carve-out is the one to watch. The 50-tonne threshold applies to iron and steel, aluminium, fertilisers and cement. It does not apply to imports of electricity or hydrogen. For electricity and hydrogen that are otherwise within the scope of Regulation (EU) 2023/956, Article 2a provides no mass-based exemption; small volume alone therefore does not take those imports outside CBAM. The Commission’s own account of the change describes a threshold designed to release the large number of very small importers while keeping the great majority of embedded emissions in scope, so the relief is real for occasional importers and largely irrelevant for the industrial volumes that drive the regime.

Embedded emissions: the definitive methodology

The definitive regime changes the methodology for determining embedded emissions, but it does not establish actual emissions as the mandatory general method. Under Article 7, embedded emissions in goods other than electricity may be determined either from actual emissions or by reference to default values. Imported electricity is determined using default values unless the criteria for using actual emissions are met. Where actual emissions are used, they must be verified in accordance with Article 8.

Guidance No. 3 addresses the calculation of embedded emissions, while Guidance No. 2 provides a shorter route into the material for non-EU operators. Where an installation operator chooses to provide actual emissions data for use in a CBAM declaration, the applicable methodology requires monitoring and the actual values must be verified before they are used. However, operators established outside the EU are not obliged to participate in CBAM monitoring, and an authorised CBAM declarant that does not receive verified actual data may use the Commission’s default values.

This is also where CBAM starts to resemble other emissions-linked reporting an institution may already run. The data discipline behind a defensible embedded-emissions figure has more in common with the assurance work under CSRD sustainability reporting than with a customs classification exercise, even though CBAM sits on the customs side of the house.

The free allocation adjustment decides how much you pay

The number of certificates an authorised CBAM declarant must surrender is determined from the declared embedded emissions after any applicable Article 9 carbon-price reduction and the Article 31 free-allocation adjustment. Implementing Regulation (EU) 2025/2620 sets the free-allocation adjustment for electrical energy at zero; for other CBAM goods the adjustment is calculated using the applicable CBAM benchmark and, where relevant, the cross-sectoral correction factor. Article 31 of Regulation (EU) 2023/956 sets the adjustment, and it tracks Article 10a of the EU ETS Directive 2003/87/EC, under which free allocation for CBAM sectors is being phased out on a fixed schedule.

Under current Article 10a(1a) of the EU ETS Directive, the legal CBAM factor represents the remaining free-allocation factor: 97.5% in 2026, 95% in 2027, 51.5% in 2030 and 14% in 2033, with no CBAM factor applying from 2034. The arithmetic complements of those figures are 2.5%, 5%, 48.5% and, from 2034, 100%, but those percentages are not themselves the legal CBAM factor and do not by themselves determine the certificate obligation. Implementing Regulation (EU) 2025/2620 calculates the free-allocation adjustment using the applicable CBAM factor, CBAM benchmark and, where relevant, the cross-sectoral correction factor; the free-allocation adjustment for electricity is zero.

The free-allocation adjustment reduces the certificate obligation during the phase-out of EU ETS free allocation. Under current law, the arithmetic complement of the legal CBAM factor rises from 22.5% in 2029 to 48.5% in 2030; the legal CBAM factor itself falls from 77.5% to 51.5%. The actual certificate requirement must still be calculated using the detailed free-allocation rules rather than applying the complementary percentage directly to embedded emissions.

Certificates: how they are priced, bought and surrendered

From 1 February 2027, Member States sell CBAM certificates to authorised CBAM declarants through the common central platform. The ordinary certificate price is based on weekly averages of EU ETS auction closing prices; for emissions declared in respect of 2026, the price is instead the quarterly average for the quarter in which the goods were imported. Where embedded emissions are based on actual emissions, Article 9 permits a reduction in the number of certificates for an eligible carbon price effectively paid in the third country, subject to the prescribed evidence and independent certification. Where embedded emissions are determined using default values, that reduction may be claimed only by reference to yearly default carbon prices.

Timing is the operational trap. Certificates cannot be bought until sales open on 1 February 2027, and the first surrender is due 30 September 2027, so the entire 2026 exposure is settled in a single 2027 window instead of accruing month by month. A declarant that imported heavily in early 2026 does not buy certificates against those goods until more than a year later, and needs to hold both the emissions evidence and the budget until the surrender date. This mechanic differs from the continuous cost of an internal carbon charge, and it interacts with the planned CBAM scope extension to downstream goods, which would widen the range of imports feeding future surrender windows.

What non-EU operators have to hand over

The sector guides, 5a through 5f, are written for that producer, mapping the production processes and value chains that determine which emissions count as embedded across the six covered sectors. Each guide carries worked examples so an operator can see how its own process translates into the figures its EU customers need.

Where a declarant intends to use actual values, it depends on the non-EU operator for the required emissions and monitoring information, and those actual values must be verified by an accredited verifier before use in the CBAM declaration. If verified actual data are not supplied, the declarant may instead use the applicable Commission default values. The evidence route for a third-country carbon price also differs depending on whether actual emissions or default values are used.

Frequently Asked Questions

If I only import a few small parcels of steel each year, am I automatically exempt under the 50-tonne threshold?

For the four mass-based sectors, the exemption applies if the cumulative net mass does not exceed 50 tonnes in the calendar year, and the exemption must be declared in the relevant customs declaration. If the threshold is exceeded, the CBAM obligations apply to all covered goods imported in that calendar year. Article 2a does not apply to electricity or hydrogen.

Does the definitive regime let me keep using Commission default values the way I did in the transitional period?

For goods other than electricity, Article 7 expressly permits embedded emissions to be determined either from actual emissions or by reference to default values. Electricity uses default values unless the criteria for actual emissions are met. Actual emissions must be verified before they are used in the CBAM declaration; a supplier is not required to establish an actual-emissions monitoring system merely because the definitive period has begun.

My supplier already pays a carbon price in its own country. Does that remove my CBAM obligation?

A qualifying third-country carbon price can reduce the number of CBAM certificates to be surrendered, but the method depends on the emissions basis. Where actual emissions are used, the reduction may reflect the carbon price effectively paid, subject to the required documentation, evidence of payment and independent certification. Where embedded emissions are determined using default values, the reduction may be claimed only by reference to the applicable yearly default carbon price. The CBAM declaration obligation is not removed by that reduction.

Who actually files the CBAM declaration, the EU importer or the non-EU manufacturer?

The annual CBAM declaration is filed by the authorised CBAM declarant, which is the importer or, where applicable, the indirect customs representative responsible under the Regulation. A non-EU installation operator may provide the actual emissions and monitoring information needed for the actual-values route; if verified actual data are not supplied, the authorised declarant may use the applicable default values. Responsibility for the declaration and certificate surrender remains with the authorised CBAM declarant.

Certificates are not sold until February 2027. What am I actually required to do during 2026?

For non-exempt imports, ensure that the applicable authorisation route is valid: hold authorised CBAM declarant status unless the Article 17(7a) provisional route applies to an application submitted by 31 March 2026. Keep records supporting the emissions method that will be used in the 2027 declaration. If actual values are used, they must be supported by the required monitoring and verification; otherwise the permitted default-value method may be used.

How do I know how many certificates my 2026 imports will cost before the surrender date?

The certificate requirement starts from declared embedded emissions and is reduced by the applicable free-allocation adjustment and, where available, the Article 9 carbon-price reduction. The legal Article 10a CBAM factor for 2026 is 97.5%, not 2.5%, and the free-allocation adjustment is calculated under Implementing Regulation (EU) 2025/2620 rather than by simply multiplying embedded emissions by 2.5%. For emissions declared in respect of 2026, the certificate price is based on the quarterly average of EU ETS auction closing prices for the quarter of importation.

Related Articles

• CBAM Indirect and Embedded Emissions for Importers: how direct and indirect embedded emissions are defined and reported under the mechanism.
• CBAM Scope Extension to Downstream Goods: the proposed widening of CBAM coverage beyond the six current sectors.
• CSRD Sustainability Reporting: the EU sustainability reporting regime and the assurance discipline behind emissions data.
• EU Tax Simplification Package 2026: the DAC recast and the broader push to cut cross-border reporting burdens.
• EU Taxonomy Disclosure Simplification: the Article 8 KPI changes reshaping green-activity disclosure.

Key Takeaways

• The first annual CBAM declaration and first certificate surrender, both for 2026 imports, are due 30 September 2027; sales of CBAM certificates open 1 February 2027.
• From 1 January 2026, Article 4’s authorised-declarant rule applies to non-exempt CBAM imports, subject to Article 17(7a), under which an importer or indirect customs representative that submitted an application by 31 March 2026 may continue importing provisionally until a decision is taken. The authorisation procedure is governed by Implementing Regulation (EU) 2025/486 as amended by Implementing Regulation (EU) 2025/2549.
• The 50-tonne annual net-mass exemption in Regulation (EU) 2025/2083 covers iron and steel, aluminium, fertilisers and cement, and does not apply to electricity or hydrogen.
• For goods other than electricity, the definitive regime permits either verified actual embedded-emissions data or the applicable Commission default values; electricity uses default values unless the conditions for actual emissions are met.
• Certificates are reduced by the free-allocation adjustment under Article 31 and Implementing Regulation (EU) 2025/2620. Under current Article 10a(1a) of the EU ETS Directive, the legal CBAM factor is 97.5% in 2026, 95% in 2027, 51.5% in 2030 and 14% in 2033; no CBAM factor applies from 2034.
• Certificate prices follow the EU ETS auction price in EUR per tonne of CO2, a quarterly average for 2026 imports and a weekly average from 2027.
• The 14 August 2026 package is ten guidance documents, four general and six sector-specific, aimed at non-EU operators, authorised declarants and verifiers.

Sources and References

• European Commission, “The European Commission publishes a series of guidance documents to support CBAM implementation in the definitive period” (14 August 2026)
• Regulation (EU) 2023/956 establishing a Carbon Border Adjustment Mechanism (EUR-Lex)
• Regulation (EU) 2025/2083 amending Regulation (EU) 2023/956 (CBAM simplification, EUR-Lex)
• Commission Implementing Regulation (EU) 2025/486 of 17 March 2025 on the authorisation of CBAM declarants (EUR-Lex)
• Commission Implementing Regulation (EU) 2025/2549 amending and correcting Implementing Regulation (EU) 2025/486 (EUR-Lex)
• Commission Implementing Regulation (EU) 2025/2620 on calculation of the free allocation adjustment (EUR-Lex)
• European Commission, CBAM definitive regime (Taxation and Customs Union)
• European Commission, Carbon Border Adjustment Mechanism overview (Taxation and Customs Union)
• Directive 2003/87/EC (EU Emissions Trading System Directive), Article 10a on free allocation (EUR-Lex)

Where the 2027 clock leaves importers now

The guidance package does not change the statutory deadlines. During 2026, importers should ensure that the applicable authorisation or valid Article 17(7a) provisional application route is in place and that their records support the emissions method they intend to use, whether verified actual values or permitted defaults. Certificate sales begin on 1 February 2027, followed by the first declaration and certificate surrender for 2026 imports on 30 September 2027. Where actual values will be used, supplier arrangements should cover the required monitoring, verification and data transfer.

Disclaimer: The information on RegReportingDesk.com is for educational and informational purposes only. It does not constitute legal, regulatory, tax, or compliance advice. Always consult your compliance officer, legal counsel, or the relevant supervisory authority for guidance specific to your institution.