Find out what UK CBAM will cost your business in 2027.
Get a free estimate of your UK CBAM levy.
Try the free estimateYou must register for UK CBAM if either test is true
You expect to import £50,000 or more of CBAM goods in the next 30 days
You have imported £50,000 or more in the previous 12 months, checked on the 1st of each month
CBAM goods are imports in five sectors
Aluminium · Cement · Fertiliser · Hydrogen · Iron and steel
Imports before 1 January 2027 do not count. Below the threshold you have no CBAM obligations.
How it works
Upload your imports
A CSV or Excel file with commodity codes, origins and weights. Our template has the columns.
We price each line
Each commodity code is matched to the CBAM scope and priced on default emission values.
Get the PDF by email
Your estimated levy on default values, the figure with verified supplier data beside it, and the line detail.
The five CBAM sectors
| Aluminium | Unwrought, bars, rods, profiles |
| Cement | Portland, aluminous, hydraulic |
| Fertiliser | Urea, ammonium nitrate, UAN |
| Hydrogen | Pure hydrogen gas |
| Iron and steel | Pig iron, ferroalloys, flat, long, pipe, stainless |
What the regulation says
UK CBAM puts a carbon price on imports of aluminium, cement, fertiliser, hydrogen, and iron and steel. Importers who meet the threshold register with HMRC, report the embedded emissions in their imports and pay the levy, at a rate set from the UK ETS price.
See what your report looks like
- Your estimated levy on default values, with the range across the assumed rate
- With verified supplier data, the same imports at 40% below default
- Line detail: each in-scope line with its code, origin, tonnes and emissions
Sent as a PDF to your inbox.
Sample data
What you would owe
On default values, no supplier data
With verified data 40% below default
£8,514 to £13,379 at £35–£55 per tonne CO₂e.
Line detail
| Product | Code | Origin | Tonnes | tCO₂e/t | tCO₂e | Exposure |
|---|---|---|---|---|---|---|
| Aluminium profiles | 76042990 | CN | 6.2 | 15.1 | 93.6 | £4,213 |
| Hot-rolled steel plate | 72085200 | TR | 42 | 1.92 | 80.6 | £3,629 |
| Portland cement | 25232900 | EG | 60 | 0.8 | 48 | £2,160 |
| Hex bolts | 73181590 | IN | 9.5 | 2.21 | 21 | £945 |
| Total · 4 in-scope lines | 117.7 | 243.2 | £10,947 | |||
These figures use default emission values. HMRC hasn't published UK values yet, so we use the European Commission's published defaults where they exist and sector averages otherwise. If your suppliers emit less than the default, you're overpaying, and verified supplier data is how you prove it.
Prepare the return with Oportax
CBAMcheck gives you the estimate. Oportax tracks your imports, collects verified emissions from your suppliers, and prepares the return and audit pack for you or your customs agent to submit to HMRC.
- Your imports tracked from your customs data
- Supplier requests in their language, chased until they reply
- The return and audit pack, prepared for you or your customs agent to submit
Frequently asked questions
What is the UK CBAM?
The UK Carbon Border Adjustment Mechanism is a carbon levy on imports of certain carbon-intensive goods. It ensures imported goods face a comparable carbon price to those produced domestically under the UK Emissions Trading Scheme.
When does UK CBAM take effect?
UK CBAM takes effect on 1 January 2027. The first reporting period covers calendar year 2027, with annual returns. Quarterly reporting begins in 2028.
Which goods are in scope?
Aluminium, cement, fertiliser, hydrogen, and iron and steel, by commodity code.
Is there a de minimis threshold?
Yes: £50,000 of CBAM goods. See the two tests above.
How is the CBAM liability calculated?
The embedded emissions in your imports, multiplied by the CBAM rate.
What data do I need to estimate my liability?
Commodity codes, countries of origin and import weights. Your customs data has all three.
What emission values does the estimate use?
These figures use default emission values. HMRC hasn't published UK values yet, so we use the European Commission's published defaults where they exist and sector averages otherwise. If your suppliers emit less than the default, you're overpaying, and verified supplier data is how you prove it.
Do I need to register with HMRC?
If you meet the £50,000 threshold during 2027, you must register with HMRC by 31 January 2028.
How is UK CBAM different from EU CBAM?
They are separate regimes, with different scope, calculations, reporting and timelines. Complying with one does not satisfy the other.