Full implementation of CBAM (Carbon Border Adjustment Mechanism)
By Mark Jansen, Center for Sustainable Finance
March 2026
On 1 January 2026, the EU Carbon Border Adjustment Mechanism moved into its definitive regime. In the first week, the European Commission reported that 10,483 import customs declarations involving CBAM goods were validated automatically and in real time through integrated national customs systems. This is the practical signal that CBAM is no longer only a reporting framework. It is now a live border control and compliance system.
CBAM is the EU's instrument for applying a carbon cost to certain imports in a way that mirrors the carbon price faced by EU producers under the EU Emissions Trading System. The policy rationale is carbon leakage. If EU producers face a carbon cost and imports do not, production and investment can shift to jurisdictions with a lower carbon bill. CBAM is designed to reduce that distortion in the EU market.
CBAM currently covers six sector groups: cement, iron and steel, aluminium, fertilisers, electricity, and hydrogen. Importers must account for greenhouse gas emissions embedded in these goods and, under the definitive regime, move from disclosure into an enforceable compliance cycle linked to EU ETS pricing. In the definitive regime, the authorised CBAM declarant is responsible for the annual declaration and certificate surrender cycle.
From reporting to enforceable compliance
The transitional phase began on 1 October 2023. It required quarterly reporting of embedded emissions for covered imports but no certificate purchases. The Commission describes this period as a learning phase designed to build the data pipeline and operational readiness for the definitive regime.
The 2026 step change is the role of authorisation and its integration into border processes. From 2026, imports of CBAM goods require authorised CBAM declarant status, and customs systems validate that status in real time before release for free circulation. A missing authorisation is not a late filing issue. It is a border problem.
What changes financially, and what is new since the transition began
The definitive phase is live, but the cash mechanics are staged. Certificate sales begin on 1 February 2027 for goods imported in 2026, following simplification changes adopted in Regulation (EU) 2025/2083. This sequencing turns 2026 into a high-stakes data year: the embedded emissions values gathered and validated now will set the baseline for the first financial compliance cycle once certificate sales begin. The first annual CBAM declaration and the surrender of the corresponding certificates for 2026 imports are due by 30 September 2027.
The price link is now operationalised. The Commission states that CBAM certificate prices track EU ETS auction prices, calculated as a quarterly average in 2026 and as a weekly average from 2027 onwards. That creates a direct transmission of EU ETS price dynamics into the cost of importing covered goods.
The compliance cycle also carries a liquidity and control component: from 2027, authorised declarants are expected to hold certificates at each quarter-end covering at least 50% of year-to-date embedded emissions. This is reduced from the previously planned 80% threshold under the simplification package, as reflected in current implementing rules and legal summaries. Technical operational guidance may still be refined as the framework is consolidated in official guidance and operational practice.
A gradual but locked-in cost path to 2034
The Commission frames CBAM as a phased mechanism tied to the phase-out of free allocation under the EU ETS for covered sectors. In its Q&A on the strengthening package, the Commission states that the CBAM financial adjustment will be progressively phased in, reaching full application by 2034. Near-term costs are limited while the system builds capacity, but the endpoint is explicit in the Commission's own policy framing. That makes later-decade exposure analysis a governance task, not a forecasting exercise.
Where implementation pressure is most likely to build
The first pressure point is embedded emissions data quality. Importers need documentation good enough to support an enforceable certificate obligation. The Commission also builds a financial incentive to move away from fallback approaches: its Q&A states that the mark-up applied when relying on certain default values rises from 10% in 2026 to 20% in 2027 and 30% in 2028, signalling that default pathways are designed to become progressively less attractive.
The second pressure point is registry governance and border-facing controls. Because authorisation is validated through customs systems, access governance, delegation, and internal sign-off determine whether goods clear, not whether a report is filed on time.
The third pressure point is net exposure, which depends on how third-country carbon prices are recognised and evidenced. The Commission describes the principle that a carbon price already paid in the country of origin can be deducted from the CBAM obligation, subject to conditions and proof. Further clarification on operational recognition and evidence requirements remains pending and may evolve through guidance and registry practice as the system moves into its first payment cycle.
What comes next in the EU rulemaking cycle
The Commission has proposed expanding CBAM's scope from 1 January 2028 to include specific steel- and aluminium-intensive downstream products. The proposal is subject to the EU's ordinary legislative procedure and is not yet adopted, meaning timing and final scope remain subject to negotiation.
According to the Commission’s accompanying analysis, the proposed extension would significantly broaden the number of downstream products and increase the number of importers in scope. As this is a proposal, final scope and timing remain subject to adoption. The signal for regulated firms and their financiers is that CBAM is being built as an expandable system, with periodic reviews and scope discussions designed into the policy cycle from the outset.
Why it matters for sustainable finance
CBAM is best read as a repricing mechanism for carbon-intensive supply chains, with an explicit phase-in path that the Commission frames through to 2034. For lenders, insurers, and investors, the key question is whether counterparties can operate the emissions data chain, the registry controls, and the EU ETS-linked cost exposure as the mechanism tightens over time.
Forward liability becomes increasingly mechanical once the price link and phase-in trajectory are set. Emissions data becomes a financial input as CBAM converts embedded emissions into a priced obligation, shifting verified data quality from sustainability reporting into counterparty assessment and risk pricing, especially where cost pass-through is negotiated rather than automatic.
For non-EU producers selling into the EU, the implication is operational: CBAM-grade emissions measurement and documentation increasingly becomes a condition of doing business with EU customers who cannot manage certificate exposure without credible supply-chain data.
Sources:
European Commission DG TAXUD CBAM overview page; EC DG TAXUD update on definitive regime, 14 January 2026; EC Presscorner Q&A on CBAM strengthening package (phase-in to 2034; default value mark-ups); EC Presscorner press release on downstream expansion proposal from 1 January 2028 (proposal stage); EC impact assessment SWD(2025)988 (downstream scope figures); Regulation (EU) 2025/2083 (OJ, 17 October 2025); ICAP, simplification changes including certificate sales from 1 February 2027, first surrender deadline 30 September 2027, and default carbon price publication from 2027; HFW summary of quarterly certificate holding requirement from 2027.
