UK CBAM guidance arrives: registration, records, relief and penalties
The UK CBAM has moved from consultation to instruction. In mid-July HMRC published a package of guidance built on the framework now settled in the Finance Act 2026, alongside an updated policy summary. For importers of aluminium, cement, fertilisers, hydrogen, iron and steel, this is the material to work from between now and 1 January 2027.
What the package contains
Four pieces matter most. First, guidance on registering for the scheme, including how to track the £50,000 registration threshold, which is measured against the value of CBAM goods imported over a rolling twelve-month period. Second, guidance on record-keeping: records supporting CBAM returns must be kept for six years, and the guidance sets out the penalties for getting this wrong. Third, step-by-step guidance on claiming carbon price relief, the mechanism that reduces UK CBAM liability where a carbon price has already been paid overseas. Fourth, published a few days earlier, drafts of the Force of Law Notice, the System Boundaries document and a Carbon Pricing Verification Form, which together carry much of the technical detail of how emissions and overseas carbon prices will be evidenced.
What it tells us
The shape of the scheme is now firm. The UK CBAM is a tax, with returns and payments rather than certificates. The £50,000 threshold keeps the smallest importers out. Relief for overseas carbon pricing will be real but evidenced, which means paperwork from suppliers, not assertions. And the six-year record-keeping requirement, backed by penalties, signals that HMRC intends to audit this tax like any other.
Some detail is still to come. Further material on monitoring and reporting requirements and on the methodology for default emissions values is expected later in 2026. Those defaults matter, because importers without actual data from their suppliers will fall back on them.
What importers should do now
Work out whether you will cross the registration threshold, and map which of your products fall within the commodity codes in scope. Read the draft System Boundaries document against your own supply chain. Start the conversation with overseas suppliers about emissions data and carbon price evidence, because both take time to produce and the relief claim will need the verification form completed properly. And brief your finance team: transitional easements extend the first deadlines for registration, returns and payment, but the liability itself accrues from day one.
The pattern from the EU scheme is clear. The businesses that struggled were the ones that waited for every rule to be final before acting. The rules are now final enough to start.
CBAM-Assured provides UK CBAM training and helps importers build the supplier data and evidence they will need from January. Contact us to get ready.