What does a UK CBAM return need for each shipment?
Each consignment goes on its own line, and different CBAM goods in one shipment are split too. Each line needs the 8-digit commodity code in force at the tax point, net weight in kg, emissions intensity per functional unit or the default, carbon price paid in pounds, country of origin, and for 2027, the quarter.
The six fields
- Commodity code: 8 digits, the one in force when the good passed the tax point.
- Net weight in kilograms at import, without packing.
- Emissions intensity in tCO2e per functional unit, or HMRC's default value where no verified figure exists.
- Carbon price the goods bore under a qualifying scheme, if any, in pounds.
- Country of origin under non-preferential rules.
- For the first accounting period, 2027 only, the quarter in which the good passed the tax point.
Splitting lines
- Several consignments of the same good: one line each.
- Different CBAM goods in the same shipment: one line each.
What to put in your shipping file
Per invoice line: the 8-digit code, net weight in kg, and the verified intensity or summary reference for that product. Your buyer can copy these straight onto the return.
One container, two goods
- Container to Felixstowe, cleared 14 May 2027: 18,400 kg of bolts and 6,200 kg of nuts.
- Return lines: two, one per commodity code, each with its own weight and intensity.
- Quarter field: second quarter of 2027.
- A second container of bolts in June: a third line, even though the code is the same.
What Senseible does here
Senseible reads quantities from your sales and freight documents, so the weight per product line matches what you shipped. We build the figure from your records and check every figure in-house; for the UK it must then be verified by a verifier accredited for UK CBAM. Have your own verifier? Send it to them.
Sources: HMRC, Carbon Border Adjustment Mechanism (CBAM): Policy summary (updated 2 November 2026)
Last reviewed 2026-11-03.