On August 14, 2026, the European Commission's Directorate-General for Taxation and Customs Union (DG TAXUD) published the first comprehensive guidance series for the Carbon Border Adjustment Mechanism (CBAM) definitive period, which has applied since January 1, 2026. The ten documents, four general guides and six sector-specific guides, set out how non-EU operators, authorised CBAM declarants and verifiers must calculate actual embedded emissions, apply the free allocation adjustment and run monitoring plans for 2026 imports. The series resolves the methodology questions compliance teams have flagged since the definitive regime turned CBAM from a reporting exercise into a financial obligation with certificate surrender.
The guidance is the operational manual for Regulation (EU) 2023/956 as it stands in its definitive phase. It does not change the underlying obligations, but it tells affected operators and declarants exactly how to discharge them for 2026 imports, which is the first year surrender of CBAM certificates applies.
Who must act on the guidance, and why now?
The definitive period, which began on January 1, 2026 under Regulation (EU) 2023/956, replaced the transitional reporting-only regime with registration, accredited verification and CBAM certificate surrender for importers of iron and steel, aluminium, cement, fertilisers, hydrogen and electricity above the EUR 50-tonne annual de minimis threshold per importer. The guidance is aimed primarily at operators of installations outside the EU that produce CBAM goods, but authorised CBAM declarants and verifiers must align their processes with the same methodology.
For 2026 imports, the series pushes operators toward actual embedded-emissions values rather than the Commission's default values. That choice is not cosmetic: actual values feed directly into the number of certificates a declarant must surrender, so the calculation method has an immediate cash impact. Operators who cannot evidence actual emissions fall back on default values, which the guidance treats as a constrained fallback, not a neutral option.
What changes against the transitional period?
The transitional period, from October 1, 2023 to December 31, 2025, required quarterly reports and accepted default values where actual data was unavailable. Guidance No. 3 (Calculation of embedded emissions) and Guidance No. 4 (Calculation of the free allocation adjustment) codify the definitive-period methodology that replaces that lighter regime.
Guidance No. 3 details the monitoring and reporting obligations for any producer of CBAM goods, including how to establish a Monitoring Plan and the limited conditions under which the Commission's default values may still be used. Guidance No. 4 explains how the free allocation adjustment reduces the number of CBAM certificates to be surrendered to account for free allowances under the EU Emissions Trading System (EU ETS), and what information declarants must collect to support that adjustment. Verification by an accredited verifier becomes mandatory, so the data architecture behind actual-emissions reporting must be audit-ready, not merely internal.
| Guidance | Topic | Focus |
|---|---|---|
| No. 1 | Introduction to CBAM concepts | Compliance cycle, roles, milestones, deadlines, exemptions |
| No. 2 | Quick guide for non-EU operators | Roadmap to emissions monitoring key concepts |
| No. 3 | Calculation of embedded emissions | Monitoring and reporting obligations, default values |
| No. 4 | Free allocation adjustment | Adjusting certificates for EU ETS free allocation |
| No. 5a | Cement | Sector processes, value chains, worked examples |
| No. 5b | Hydrogen | Sector processes, value chains, worked examples |
| No. 5c | Fertilisers | Sector processes, value chains, worked examples |
| No. 5d | Iron and steel | Sector processes, value chains, worked examples |
| No. 5e | Aluminium | Sector processes, value chains, worked examples |
| No. 5f | Electricity | Sector processes, value chains, worked examples |
What does the sector-specific scope add?
Guidance documents 5a to 5f cover cement, hydrogen, fertilisers, iron and steel, aluminium and electricity respectively. Each sets out the production processes, value chains and monitoring and reporting considerations specific to that sector, supplemented with worked examples. For iron and steel and aluminium, where complex downstream value chains and alloying inputs drive embedded-emissions calculations, the sector guides narrow the methodology that the general Guidance No. 3 leaves open. Operators should map each installation to its sector guide before finalising the Monitoring Plan, because a mismatch between the chosen calculation route and the sector guide will surface at verification, not before.
The full series is hosted on the CBAM legislation and guidance page, where DG TAXUD will add further language versions as they become available.
Continuous, per-jurisdiction monitoring surfaces guidance publications like this the moment they go live, so compliance teams can recalibrate definitive-period obligations without manual watchkeeping across the EU and each national competent authority.
Take advantage of this real-time watch
What to do next
Confirm whether your installations fall under one of the six sector guides, align the Monitoring Plan with Guidance No. 3, and brief verification and customs teams on the free allocation adjustment mechanics in Guidance No. 4 before the first annual declaration covering 2026 imports falls due. Treat actual-emissions data collection as the critical path: without verified actual values, default values apply and the certificate surrender position worsens. Obsidian tracks CBAM developments across the EU institutions and each national competent authority so teams can act on guidance the day it publishes.
