There are now two carbon border taxes on the same short list of heavy materials, one on each side of the Channel. They look alike, and they will probably be brought closer together, but today they have different start dates, thresholds, deadlines and ways of paying. This post sets them side by side and then covers what a UK business that sells these goods into the EU needs to do.
The two schemes side by side
| UK CBAM | EU CBAM | |
|---|---|---|
| Starts | 1 January 2027 | Definitive regime since 1 January 2026 (reporting-only transitional period from October 2023) |
| Law | Finance Act 2026, with regulations and notices | Regulation (EU) 2023/956, as amended by Regulation (EU) 2025/2083 |
| Goods | Aluminium, cement, fertiliser, hydrogen, iron and steel. Electricity is not covered | Aluminium, cement, fertilisers, hydrogen, iron and steel, and electricity |
| Who has to take part | Importers whose CBAM goods reach £50,000 in value over 12 months (or are expected to over the next 30 days) | Importers bringing in more than 50 tonnes of CBAM goods a year, who need authorised CBAM declarant status |
| Who pays | The importer, as a tax on a CBAM return to HMRC | The importer, by buying and surrendering CBAM certificates |
| Price | A rate per tonne of CO2e for each sector, set each quarter from the UK ETS price and adjusted for free allowances | Based on the EU ETS auction price: a quarterly average in 2026, a weekly average from 2027 |
| First deadline | Return and payment for calendar 2027 by 31 May 2028, then quarterly from 2028 | Declaration and certificate surrender for 2026 imports by 30 September 2027, then every 30 September |
| Emissions counted | Direct emissions embodied in the goods | Direct emissions, plus indirect emissions (from electricity used) for cement and fertilisers |
| No producer data? | Government default values, with a 10% markup in every sector except fertiliser | EU default values |
| Carbon price paid abroad | Carbon Price Relief, with a verified form | Deduction for a carbon price effectively paid |
The UK details come from the government's policy summary, updated on 16 October 2026. The EU details come from the European Commission and Regulation (EU) 2025/2083, which simplified the EU scheme and replaced the old value threshold with the single 50-tonne threshold. For the UK side in full, read our complete guide to the UK CBAM.
The differences that matter in practice
- A tax return against a certificate market. A UK importer files a return to HMRC and pays a tax worked out at the published rate for the quarter. An EU importer has to become an authorised CBAM declarant, buy certificates from its national authority and hand them over once a year.
- Value against weight. The UK threshold is £50,000 of CBAM goods; the EU one is 50 tonnes. A firm bringing in a small tonnage of expensive aluminium parts can be under one and over the other.
- Electricity. Only the EU taxes imported electricity. It matters for interconnector trading, not for most businesses.
- Which emissions count. The UK charge is on the direct emissions embodied in the goods. The EU also counts the indirect emissions from the electricity used to make cement and fertilisers.
- Timing. The first EU declaration and certificate surrender, for goods imported in 2026, is due by 30 September 2027. EU countries start selling certificates on a common central platform from 1 February 2027. The first UK return, covering the whole of 2027, is due by 31 May 2028.
What the two have in common matters more for most businesses: both charge on emissions per tonne of product, both prefer verified figures from the installation that made the goods, both fall back to default values that are deliberately not generous, and both give credit for a carbon price already paid where the goods were made. To see how a UK bill is built up, read how to work out a UK CBAM bill.
Does the UK CBAM exempt EU goods, or the EU CBAM exempt UK goods?
Not yet. The UK policy summary says no jurisdictions are currently exempt from the UK CBAM, and UK goods are covered by the EU CBAM. The likely route to change is linking the UK and EU emissions trading schemes, which both sides agreed at the May 2025 summit to work towards. Their common understanding from that summit says a linking agreement should give mutual exemptions from each other's CBAM.
On 7 October 2026 POLITICO reported that a deal to link the two schemes had been reached and would be announced at a UK-EU summit. The Prime Minister has said that summit will be in Brussels on 20 November 2026. As of 19 October 2026, neither government has confirmed a deal, no text has been published and no start date has been given. A linked scheme would be expected to bring mutual CBAM exemptions, but only once a link is agreed, signed and in force. Until then, plan on both schemes applying as they stand. We will update this post when anything is published.
What UK exporters to the EU need
If you make or sell steel, aluminium, cement, fertiliser or hydrogen and your customers are in the EU, the EU CBAM is already part of your sales conversation.
- Your EU customer is normally the one who pays. The importer, or its indirect customs representative, is the authorised CBAM declarant and surrenders the certificates. You are not, unless you are the importer.
- You will be asked for verified emissions per tonne. Without your figure your customer has to use the EU default value, which usually means a bigger bill. A verified figure below the default is worth real money to them, and can win or keep the order.
- You may be the importer. If you sell on delivered duty paid terms through an EU company, or bring goods into the EU yourself, that EU company is the importer. A business not established in the EU has to use an indirect customs representative, and that representative must hold authorised CBAM declarant status. The 50-tonne threshold applies per importer, per year.
- Your figure may be useful twice. If you also import CBAM goods into the UK, or sell to UK firms that do, the same monitoring can support UK CBAM data, as long as it meets the UK's own verification rules.
If you are on the other side, buying from overseas, our post on how to ask an overseas supplier for CBAM emissions data has an email template you can send. And because the same per-tonne figure improves your carbon footprint, read CBAM data and your Scope 3. The free UK CBAM registration checker tells you whether you will need to register in the UK, and our earlier post on what UK CBAM means for suppliers covers the questions customers will ask.
How Carbon Recycling helps
Carbon Recycling is not a CBAM verifier or a customs agent, and it doesn't file CBAM returns or declarations in either country. It helps with the carbon reporting around them.
On the Growth plan, supplier data requests let you ask a supplier for its emissions through a secure link with no account needed on their side. You can put your CBAM questions in the request message, review the figure and method they send, and add it to your Scope 3. The CBAM pack, coming soon, works out the embedded emissions and the UK CBAM charge on your imports. If your group has EU companies or sites, the Enterprise plan covers several companies with a group report, and sites outside the UK, with each country's own electricity factor, for £99 a month per country.
The 14-day free trial lets you add data and see how your reports look. Printing, saving and downloading need a paid plan.