The United Kingdom has published the technical and compliance framework for its Carbon Border Adjustment Mechanism (CBAM), setting out the requirements importers and overseas producers will face when the system takes effect on 1 January 2027. HM Revenue & Customs (HMRC) released the package on 16 October 2026, covering emissions calculations, default values, independent verification, record-keeping and the methodology for determining CBAM rates.
With less than three months remaining before implementation, the guidance establishes the operational requirements for trade in five covered sectors: iron and steel, aluminium, cement, fertilisers and hydrogen. Electricity is excluded from the UK mechanism, distinguishing its sectoral scope from that of the European Union’s CBAM.
Five sectors covered under the UK mechanism
The exclusion of electricity represents a significant structural difference between the UK and EU carbon-border regimes. The EU mechanism includes electricity as a dedicated sector, with specific provisions governing actual emissions and cross-border contractual arrangements.
For companies exporting to both markets, the two systems will therefore require separate assessments of product coverage and compliance obligations. Although both mechanisms address the carbon content of imported goods, their scope, pricing arrangements and reporting procedures are not identical.
The newly published UK guidance provides importers and foreign producers with a clearer framework for determining which emissions data can be used for customs-related CBAM reporting. It also establishes the conditions under which actual installation-level emissions may replace HMRC’s prescribed default values.
Verified emissions data and default values
Overseas installations seeking to supply actual emissions figures for UK CBAM reporting must monitor their emissions throughout a full calendar year. The resulting data must be verified by an eligible independent verifier before importers can use the actual values under the framework.
Where the necessary monitoring records and verification are unavailable, the importer must apply the relevant HMRC default values. This makes the availability of verified emissions information a direct consideration in the commercial relationship between overseas producers and UK customers.
Producers must consequently determine before the mechanism begins whether they can establish a verified actual-emissions reporting route or whether their UK customers will need to rely on default figures. That decision can affect commercial pricing, contractual provisions, customer selection and working-capital requirements.
The requirements also place greater importance on access to qualified independent verifiers and on maintaining emissions records that meet the applicable reporting conditions. For exporters, emissions monitoring and verification must form part of routine trade operations rather than being addressed only after the mechanism enters into force.
Quarterly rates linked to the UK Emissions Trading Scheme
The UK CBAM will use a quarterly pricing structure, with rates adjusted to reflect the effective carbon price under the UK Emissions Trading Scheme (UK ETS). Separate rates will apply to each covered sector, and the first live rates are scheduled to take effect from the beginning of 2027.
The UK approach differs from the EU’s certificate-pricing arrangements. EU CBAM certificate prices are derived from EU ETS auction prices. Under the EU system, quarterly certificate pricing applies in 2026, with a transition to weekly pricing from 2027.
These differences mean that exporters supplying both the UK and EU markets will need to account for separate carbon-pricing methodologies and compliance processes. The mechanisms share the objective of addressing emissions associated with imported goods, but their pricing schedules and administrative requirements remain distinct.
Steel and aluminium exporters face separate compliance requirements
For steel and aluminium producers in Southeast Europe, the UK guidance highlights the need to align plant-level emissions monitoring with the requirements of individual destination markets.
A single installation-level emissions file may not be sufficient to meet both UK and EU reporting requirements without additional processing. Producers may need to map their emissions data to different product groupings, verification standards and importer reporting structures.
A common monitoring, reporting and verification (MRV) system at plant level can support data collection across export markets, but it does not remove the need for market-specific compliance procedures. Companies serving both jurisdictions will still need to account for differences in the treatment of products, emissions information and reporting obligations.
The ability to provide verified actual-emissions data may also become a factor in supplier selection and contract negotiations. Where verification is unavailable and default values must be applied, the resulting carbon-related liability may be higher or less predictable for the importing customer.
Carbon-adjusted costs enter trade finance and procurement
The new requirements also have implications for banks and trade-finance providers handling transactions in covered commodities. Lenders and financing counterparties will need to distinguish between the headline commodity price and the carbon-adjusted landed cost of imported goods.
A supplier unable to provide verified emissions data may expose its customer to a default-based CBAM liability that is higher or less predictable than one based on verified actual values. This can influence credit limits, procurement terms and the financial conditions attached to cross-border transactions.
For exporters, the commercial consequences extend beyond emissions reporting itself. Access to verification, the reliability of installation-level records and the allocation of carbon-border costs in contracts can all affect the terms on which goods are supplied to UK buyers.
HMRC’s publication on 16 October 2026 provides the operational framework ahead of the mechanism’s scheduled launch on 1 January 2027, establishing the requirements for emissions data, independent verification, default values, record retention and sector-specific carbon pricing under the UK CBAM.
