UK CBAM guidance
UK CBAM for customs brokers
Brokers will be central to the CBAM data flow. The importer, however, should be clear about who is legally liable and who owns the tax-return process.
Last updated: 13 August 2026
Where brokers can add immediate value
CBAM starts with declaration-level information. Brokers can help clients identify candidate commodity codes, supply tax-point dates, values and weights, and establish a repeatable export or report. This is valuable even for clients that are below the registration threshold today.
Clarify responsibility early
HMRC’s guidance says the importer is generally the person named on the import declaration where customs duty is due, including where another person declares on their behalf. A broker should avoid assuming that a client’s CBAM legal liability transfers merely because the broker files the customs entry.
| Broker can support | Importer should own or confirm |
|---|---|
| Commodity-code reports and declaration extracts | Whether the imports are in scope and whether to take classification advice |
| Tax-point, value and weight data | Threshold monitoring and registration decision |
| Customs procedure and declaration context | Supplier emissions evidence and carbon-price-relief evidence |
| Data handover for a return | Return sign-off, payment and ongoing compliance |
A client-ready data pack
A useful recurring pack contains declaration reference, importer/EORI, tax-point date, 8-digit commodity code and description, net mass, customs value, origin, procedure and any relevant relief/exemption information. Keep versioning clear so a client can trace a number back to a declaration.
Questions to ask clients now
- Who is named as importer on each flow?
- Which legal entity will monitor the £50,000 tests?
- Can the client supply a current list of its supplier contacts?
- Where will the verified emissions reports be stored?
- Who is authorised to submit a CBAM return or appoint a tax agent?
Opportunity: provide a simple monthly CBAM exposure report, rather than a generic “CBAM-ready” claim. Clients need usable data and clear ownership.