Who has to pay the UK CBAM?

The importer: the business in whose name, or on whose behalf, the customs declaration is made. It applies to aluminium, cement, fertiliser, hydrogen, and iron and steel goods imported into the UK from 1 January 2027. You must register with HMRC once the customs value of your CBAM imports reaches £50,000, over the last 12 months or expected in the next 30 days; in 2027 you only count imports from 1 January 2027.

Which CBAM rate does the pack use?

The rate for the sector and the quarter the goods were imported in. HMRC publishes the official rates at the start of each quarter, the first (January to March 2027) before the end of 2026. Until then the pack uses the illustrative rates HM Treasury and HMRC published on 16 October 2026, labelled as illustrative wherever they appear, and we update every figure when the official rates come out.

What is a default value?

The government's figure for the emissions in each CBAM good, in tonnes of CO2e per tonne, listed by commodity code. You can use it when you don't have verified data from the producer. The values published on 16 Oct 2026 apply to imports in 2027 and 2028. They include a markup of 10% in every sector except fertiliser, so a producer's verified figure usually means a smaller bill. The pack shows what the markup costs you on each line.

Does the CBAM pack file my return?

No. You, or your customs agent, file the CBAM return with HMRC. The pack works out the figures, keeps a record of each import, and gives you a quarterly summary by sector and a line-by-line download to fill the return in from. It is guidance, not tax advice.

Can I use it if I export to the EU rather than import?

Yes. EU importers have owed the EU's own CBAM since January 2026 and will ask UK suppliers for emissions per tonne of product. You can use the pack to see how your figure compares with the UK default value for the same commodity code, and what that difference is worth to a customer. The EU's default values and prices are different, so it isn't a calculation of EU CBAM.

Yes. Anyone on the 14-day free trial can add imports and see the results. Downloads need a paid plan with the CBAM pack added.

Add-on products

CBAM pack: work out your UK CBAM charge

From 1 January 2027, UK importers of iron and steel, aluminium, cement, fertiliser and hydrogen pay a carbon charge on the emissions embedded in those goods. The CBAM pack works out that charge for every import, with the government's default values and the CBAM rate for each quarter, so you can budget for it and fill in your return.

Who it is for

UK businesses of any size that import iron and steel, aluminium, cement, fertiliser or hydrogen from 1 January 2027, or expect to pass the £50,000 registration threshold.
Builders' merchants, fabricators, stockholders, manufacturers and distributors who want to know what CBAM will add to the cost of imported materials.
UK producers whose EU customers ask for CBAM data, who want to see how their own emissions per tonne compare with the default value for their goods.
Accountants and customs agents who prepare figures for an importer.

What it does

Record each import: what it is, its commodity code (searchable, from HMRC's list of 570 CBAM goods), country of origin, quarter, weight and customs value.
Choose the government default value or the producer's verified actual emissions for each line.
See the embedded emissions in tonnes of CO2e and the CBAM charge at that quarter's rate, less any carbon price already paid abroad.
See what the default values' markup costs you, and what verified supplier data saves.
Totals for each quarter and each sector, ready for your CBAM return, and a running total against the £50,000 threshold.
Download every line and the quarterly summary as spreadsheets (CSV).
Rates are updated each quarter when HMRC publishes them. Illustrative rates are always labelled as illustrative.

A worked example: 500 tonnes of cement

A builders' merchant imports 500 tonnes of Portland cement (commodity code 25232900) in January to March 2027. The producer has no verified emissions data, so it uses the government default value of 1.375 tonnes of CO2e per tonne.

Embedded emissions	500 t × 1.375 = 687.5 tCO2e
CBAM rate for cement, January to March 2027 (illustrative)	£8.78 per tCO2e
CBAM charge	687.5 × £8.78 = £6,036.25
Of which the default value's 10% markup	£548.75

If the producer could give a verified figure of 1.00 tonnes of CO2e per tonne, the charge would be £4,390.00, a saving of £1,646.25. If the producer had paid a carbon price of £5.00 per tonne of CO2e under a qualifying scheme abroad, the default value charge would fall to £2,598.75.

These rates are illustrative. HM Treasury and HMRC published them on 16 Oct 2026 from preliminary data. They create no tax liability, and the official rates for January to March 2027 will be published before the end of 2026. The example's actual-data figure and foreign carbon price are made up for illustration.

The rates used

Sector	January to March 2027, £ per tCO2e (illustrative)	Default value markup
Iron and steel	£9.69	10%
Aluminium	£9.79	10%
Cement	£8.78	10%
Fertiliser	£1.45	None
Hydrogen	£9.24	10%

The CBAM rate isn't a flat carbon price. It starts from the average UK Emissions Trading Scheme auction price for the previous quarter and takes off the share of UK producers' emissions still covered by free allowances, which is why fertiliser's rate is much lower. For more background, read our explainer on the UK CBAM and what the October 2026 rates and default values mean.

What it isn't

The CBAM pack is guidance to help you budget and prepare, not tax advice. It doesn't file your CBAM return or register you with HMRC, and it doesn't verify a producer's emissions: actual data has to come from the producer, checked by an accredited verifier. HMRC's guidance on gov.uk is the authority.

Contains public sector information licensed under the Open Government Licence v3.0. Source: HMRC, Check the default values for the Carbon Border Adjustment Mechanism (CBAM). Contains public sector information licensed under the Open Government Licence v3.0. Source: HM Treasury and HMRC, Illustrative CBAM rates and worked example (16 October 2026).

Questions

Who has to pay the UK CBAM?: The importer: the business in whose name, or on whose behalf, the customs declaration is made. It applies to aluminium, cement, fertiliser, hydrogen, and iron and steel goods imported into the UK from 1 January 2027. You must register with HMRC once the customs value of your CBAM imports reaches £50,000, over the last 12 months or expected in the next 30 days; in 2027 you only count imports from 1 January 2027.
Which CBAM rate does the pack use?: The rate for the sector and the quarter the goods were imported in. HMRC publishes the official rates at the start of each quarter, the first (January to March 2027) before the end of 2026. Until then the pack uses the illustrative rates HM Treasury and HMRC published on 16 October 2026, labelled as illustrative wherever they appear, and we update every figure when the official rates come out.
What is a default value?: The government's figure for the emissions in each CBAM good, in tonnes of CO2e per tonne, listed by commodity code. You can use it when you don't have verified data from the producer. The values published on 16 Oct 2026 apply to imports in 2027 and 2028. They include a markup of 10% in every sector except fertiliser, so a producer's verified figure usually means a smaller bill. The pack shows what the markup costs you on each line.
Does the CBAM pack file my return?: No. You, or your customs agent, file the CBAM return with HMRC. The pack works out the figures, keeps a record of each import, and gives you a quarterly summary by sector and a line-by-line download to fill the return in from. It is guidance, not tax advice.
Can I use it if I export to the EU rather than import?: Yes. EU importers have owed the EU's own CBAM since January 2026 and will ask UK suppliers for emissions per tonne of product. You can use the pack to see how your figure compares with the UK default value for the same commodity code, and what that difference is worth to a customer. The EU's default values and prices are different, so it isn't a calculation of EU CBAM.
Can I try it first?: Yes. Anyone on the 14-day free trial can add imports and see the results. Downloads need a paid plan with the CBAM pack added.