Who is the importer

The rule

Section 146(1) of the Finance Act 2026 provides that the person liable to CBAM on the emissions embodied in a CBAM good is the importer. Section 144 fixes when a good is imported: for goods chargeable to import duty at a Great Britain port, when the customs declaration is accepted, whether or not any duty is payable. Section 146(2) then names the importer where liability is incurred on the acceptance of a declaration: the person in whose name the declaration for the procedure was made, or, if the declaration was made on behalf of another person, the person on whose behalf it was made. Where that does not apply, the importer is the person on whose behalf the good is imported.

The freight forwarder

When an agent lodges a declaration, the agent either acts in your name, so that you are the declarant, or acts in the agent's own name on your behalf. In the first case section 146(2)(a)(i) makes you the importer; in the second, section 146(2)(a)(ii) makes you, the person on whose behalf the declaration was made, the importer. In both cases the liability lands on you and not on the agent. The answer depends on the declaration having been made on your behalf, which is a matter of fact and of the terms on which the agent was engaged; an agent who declares on its own account, because it has bought the goods and is selling them on after clearance, is the importer and pays.

The group company abroad

If a trading company in another country sells to your UK factory and the goods are declared in the name of the UK factory or on its behalf, the UK factory is the importer. If the company abroad is itself the declarant, in its own name and on its own behalf, because it holds a UK customs registration and clears the goods before title passes, then it is the importer and is liable, wherever it is established. Nothing in Part 5 confines liability to a person established in the United Kingdom, and nothing lets a group choose which member carries the tax other than by choosing who declares. Paragraph 16 of Schedule 17 separately lets HMRC treat connected persons who have artificially separated their activities as one taxable person.

The delivered duty paid seller

Under a delivered duty paid contract the seller undertakes to clear the goods and pay the duty. If the seller does so as the declarant in its own name and on its own behalf, the seller is the importer, is liable, and must register if its imports trigger registration; the UK buyer has no return to file for those goods and should expect the tax to be priced into the contract. If instead the seller arranges clearance through an agent who declares in the buyer's name or on the buyer's behalf, which happens where the seller has no UK customs registration and uses the buyer's, the buyer is the importer regardless of what the contract says about who bears the duty. The contract allocates the cost; the Act allocates the liability; and the two can point at different people.

Special customs procedures

Section 145 applies where a CBAM good is declared for a special customs procedure, processed under it into a good that is not a CBAM good, and that good is then imported. CBAM is charged on so much of the emissions embodied in the output as were embodied in the input when it entered the procedure, and the importer of the finished product, identified by the declaration that releases it, pays on the steel that went into it. Declaring covered goods into inward processing defers the tax until release; it does not remove it.

The charge follows the threshold

Section 147(1) provides that CBAM is not charged if the importer is, at the time of import, neither registrable nor registered, or is importing otherwise than in the course of a business. A registrable person is one who has triggered registration but has not registered. The importer is therefore liable only once its own imports have crossed the threshold, or once it has registered, and section 155 treats a public authority or a charity importing for commercial purposes like any other business.

What HMRC's guidance adds

HMRC's guidance page "Check if you're classed as the importer for Carbon Border Adjustment Mechanism (CBAM)", which was published on 16 July 2026 and updated on 14 August 2026, states that where there are customs duties to pay you are the individual or organisation named on the import declaration, even if someone is declaring the goods on your behalf. It lists the people who may complete a declaration for you without becoming the importer in your place: a tax agent, an employee, a freight forwarder, a haulier, a customs broker, an express operator and a fast parcel operator. That page is guidance and not law, and it does not deal with direct or indirect representation, with a seller established outside the United Kingdom, with a group of companies, or with a delivered duty paid contract. Those answers come from section 146 of the Act, as set out above.

The check

Take the last twelve months of customs declarations for covered goods. For each, identify the declarant and, where the declaration was made on someone's behalf, the person on whose behalf it was made. That person is the importer, and the customs value on that declaration counts towards that person's threshold and appears on that person's return. Where an agent declares for you, ask the agent to confirm in writing on whose behalf each declaration was lodged, because that answer decides everything that follows.