UK CBAM Liability Calculator
Estimate your CBAM liability across multiple import lines. Compare HMRC default values against supplier data and see the cost of relying on defaults — with Carbon Price Relief estimates where applicable.
Add your import lines
Add import lines
Add one line per product or commodity code. Select the sector, enter tonnage, and choose country of origin. You can add as many lines as you need.
Describe your data position
For each line, tell us whether you have verified emissions data, whether the producer pays a carbon price, and your chosen rate scenario.
Review your liability
See your annual liability under default values and under actual data. View the gap, Carbon Price Relief, and a quarterly forecast through 2029.
Your import lines
HMRC-indicated trajectory (base assumption)
Line 1
Send a copy to your inbox
We will email you a detailed breakdown with sector-specific numbers, quarterly projections, and a checklist of next steps for collecting verified emissions data.
Frequently asked questions
Where do the default emission factors come from?
HMRC publishes default emission factors for each sector. These are conservative estimates used when verified emissions data is not available. Using defaults typically results in a higher liability.
What is Carbon Price Relief?
If your supplier has already paid a carbon price in the country of origin (e.g. EU ETS or UK ETS), you can deduct that from your CBAM liability. You need documented evidence of the carbon price paid.
How do verified emissions reduce my liability?
Verified emissions — certified by an accredited body — are often significantly lower than HMRC default values. Using verified data can reduce your liability by 30% or more.
What do the rate scenarios mean?
CBAM rates are expected to rise over time. Low, Central, and High scenarios reflect different potential trajectories. The Central scenario uses HMRC-indicated rates. Low and High apply ±20% to illustrate upside and downside risk.
Is this calculator HMRC-approved?
No. This tool provides indicative calculations for planning purposes only. All figures are marked "Provisional" because HM Treasury has not yet published final default values and rates. Always use Oremly's full platform or consult a professional for official CBAM returns.
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