CBAM 2026: What UK Exporters Need to Know Now the Definitive Period Has Begun
The EU’s Carbon Border Adjustment Mechanism entered its definitive period on 1 January 2026. After two years of transitional reporting, EU importers must now purchase and surrender CBAM certificates each year, adjusted for any verified carbon price already paid in the country of origin. This carries real financial consequences for importers and their suppliers.
What Changed in December 2025
Just weeks before the deadline, the European Commission published a package of implementing regulations that set the operational rules for the definitive phase. These include Implementing Regulation (EU) 2025/2547 covering emissions calculation methodology, Implementing Regulation (EU) 2025/2546 on verification principles, and Implementing Regulation (EU) 2025/2621 establishing the default values and benchmarks.
The default values are particularly significant. For importers unable to provide verified actual emissions data, these country and product-specific values will be used to calculate their CBAM liability. Crucially, these defaults now include a punitive markup: 10% in 2026, rising to 20% in 2027 and 30% from 2028 onwards. Fertiliser producers received more favourable treatment with a 1% markup cap.
Verification Requirements Are Now Live
The shift that will affect UK exporters most directly is the new verification framework. During the transitional period, EU importers simply reported emissions data without financial consequences or third-party validation.
From 2026, any importer wishing to use actual emissions data (rather than costly defaults) must have that data verified by an accredited auditor. This means UK manufacturers supplying the EU market need formal monitoring plans that document their methodology for collecting emissions data at installation level and calculating embedded emissions.
EU buyers are already seeking compliant monitoring plans and verified data from UK suppliers. This is not a theoretical compliance exercise; it is happening now.
Key Dates
EU importers exceeding 50 tonnes of CBAM goods annually (iron and steel, aluminium, cement and fertilisers – the threshold does not apply to hydrogen or electricity) must register as authorised declarants by 31 March 2026 to continue importing while approval is pending. Certificate purchases begin 1 February 2027, with the first surrender deadline on 30 September 2027 covering all 2026 imports.
Scope Extension Proposed for 2028
Alongside the December implementing regulations, the Commission published a proposal to extend CBAM to approximately 180 downstream products from 1 January 2028. The targeted goods are steel and aluminium-intensive products including machinery, vehicle components, domestic appliances, construction equipment and metal fabrications.
This proposal still requires approval through the ordinary legislative procedure, but the direction of travel is clear: CBAM will expand beyond basic materials to finished goods. For UK manufacturers of products containing significant steel or aluminium content, this signals future compliance requirements even if your products are not currently in scope.
What UK Suppliers Should Do
If you export steel, aluminium, cement, fertilisers or hydrogen products to EU customers, expect requests for verified emissions data. Having a compliant monitoring plan and accurate installation-level emissions calculations will differentiate your products in a market where relying on default values means higher costs for your EU customers.
The emissions calculations prepared during the transitional period provide a useful starting point, but will likely need reformatting into a formal monitoring plan aligned to the new 2025/2547 template requirements.
Need help preparing for CBAM verification? Contact Hooper & Co for specialist support on emissions calculations, monitoring plans and CBAM compliance. Email [email protected] or call to discuss your requirements.