UK CBAM: What Importers Need to Know Before January 2027

From 1 January 2027, the UK will introduce its new Carbon Border Adjustment Mechanism (CBAM), bringing new responsibilities for businesses importing certain carbon-intensive goods into the UK.

With implementation now only a few months away, businesses importing affected products should be reviewing their commodity codes, import values and supplier information to understand whether CBAM will apply to them.

What Is UK CBAM?

CBAM is a new environmental tax designed to place a carbon price on certain goods imported into the UK.

UK manufacturers in carbon-intensive industries can already face carbon costs through the UK Emissions Trading Scheme (UK ETS). CBAM is intended to ensure that comparable imported products also face a carbon price, reducing the risk of production and associated emissions simply moving to countries with lower carbon costs — often referred to as carbon leakage.

The new rules will apply to qualifying goods imported into the UK from 1 January 2027.

Which Goods Are Affected?

UK CBAM will initially apply to specified goods within five sectors:

• Aluminium
• Cement
• Fertiliser
• Hydrogen
• Iron and steel

Importantly, CBAM does not automatically apply to every product containing one of these materials.

Whether goods fall within the scope of CBAM will be determined by their commodity code, making accurate product classification particularly important.

For more information on how goods are classified for international trade, see our guide to Commodity Codes Explained.

Who Will Need to Register for CBAM?

Businesses importing £50,000 or more of CBAM goods may be required to register for the new tax.

From 1 January 2027, businesses will need to consider whether:

• They expect to import CBAM goods worth £50,000 or more within the next 30 days
• They have imported CBAM goods worth £50,000 or more during the relevant previous 12-month period

There are circumstances where certain imports may not count towards the registration threshold, including some returned goods, temporary admissions and goods subject to particular customs procedures.

Although CBAM takes effect from 1 January 2027, registration is not due to open until 1 January 2028. Businesses can still become liable during 2027, however, so it will be important to monitor affected imports and maintain the required records from the outset.

Record Keeping Will Be Important

Anyone importing CBAM goods into the UK will have record-keeping responsibilities from 1 January 2027, even where their imports remain below the £50,000 registration threshold.

HMRC requires relevant records to be retained for six years.

These records include information such as the commodity code and description of the goods, together with their net mass at the time of import.

This means businesses should not assume that being below the registration threshold removes the need to consider CBAM altogether.

Why Supplier Information Will Matter

One of the more significant changes for importers will be the increased importance of information from overseas manufacturers and suppliers.

CBAM charges will be linked to the emissions embodied in imported goods. This means businesses may need access to information about how products were manufactured and the emissions associated with their production.

Where the required actual emissions information is not available, default emissions values may be used in accordance with the CBAM rules.

For many businesses, preparing for CBAM therefore starts well before goods reach the UK border. Importers should begin speaking with suppliers now to understand what information is available and whether their existing product and supply-chain data will be sufficient.

How Will CBAM Charges Work?

The amount of CBAM payable will broadly depend on the emissions embodied in the imported goods and the relevant UK CBAM rate.

The mechanism is intended to reflect the carbon price faced by equivalent UK production. Relief may also be available where a qualifying carbon price has already been paid overseas.

Detailed requirements around emissions reporting, verification, rates and default values are continuing to develop as the January 2027 implementation date approaches.

What Should Importers Be Doing Now?

Businesses do not need to wait until January to begin preparing.

Importers potentially affected by CBAM should:

• Review the commodity codes used for imported goods
• Identify products that may fall within one of the affected sectors
• Review the value and frequency of those imports
• Establish who will be responsible for CBAM within the supply chain
• Speak with overseas suppliers about emissions information
• Ensure accurate records are available for commodity codes, product descriptions and net weights
• Monitor further HMRC guidance ahead of implementation

CBAM introduces another reason why accurate Customs and product data is becoming increasingly important across international supply chains.

How RWLS Can Help

As a freight forwarding and Customs clearance provider, RWLS can support businesses in reviewing the Customs information associated with their imports, including commodity classification and import documentation, and help identify where goods may fall within the scope of UK CBAM.

While responsibility for CBAM compliance remains with the importer, understanding which products are affected is an important first step in preparing for the new rules.

If you would like to discuss how UK CBAM may affect your imports, please contact the RWLS team.

Please note: The information in this article is based on UK Government and HMRC guidance available as at September 2026. UK CBAM requirements and supporting guidance continue to develop ahead of implementation. Businesses should check the latest HMRC guidance or seek appropriate professional advice when assessing their individual obligations.