Your EU buyer asked for CBAM data. Here's what to do this week.

If you make aluminium, steel or fastener products and sell to Europe, a CBAM data request is now a normal part of keeping the customer. Here's how to handle one without panic.

Why you're getting this request now

The EU's Carbon Border Adjustment Mechanism (CBAM) moved into its definitive regime on 1 January 2026. Before that, EU importers only had to report emissions. Now they must pay for them.

An EU company that imports more than 50 tonnes a year of CBAM goods must be an authorised CBAM declarant. It declares the emissions embedded in everything it imported during the year and surrenders CBAM certificates to cover them. For goods imported in 2026, the first declaration and certificate surrender are due by 30 September 2027. Certificate sales open on 1 February 2027.

That's why your buyer's sustainability or customs team is writing to suppliers now. They need your numbers well before September 2027, and they need time to have them checked.

What happens if you don't reply

If a supplier can't provide usable data, the importer has to use the EU's default values for your product and country. Default values are deliberately set high, and a mark-up is added on top: 10% in 2026, 20% in 2027 and 30% from 2028. Higher emissions on paper means more certificates and a higher cost for your buyer.

In practice, suppliers who send clean data become cheaper to buy from. Suppliers who don't may lose orders to someone who does.

Step 1: Work out what they actually sent

Requests usually arrive in one of three forms:

• The Commission's communication template. An Excel workbook the European Commission publishes so installations outside the EU can pass emissions data to importers. The Commission also publishes filled examples by sector, including aluminium and steel.
• The buyer's own questionnaire. Some importers build their own form or supplier portal. It usually asks for the same core data in a different layout.
• A request to register in the CBAM Registry. Non-EU installation operators can register in the EU's CBAM Registry and share installation and emissions data with their customers there.

Look for the reporting period (usually calendar year 2026, sometimes split by quarter or shipment), the products and CN codes they list, and the deadline.

Step 2: Check your product is in scope

CBAM covers six sectors: iron and steel, aluminium, cement, fertilisers, hydrogen and electricity. What counts is the CN code (the EU customs code) of the goods you ship. Aluminium goods sit in chapter 76, for example unwrought aluminium (7601) and bars, rods and profiles (7604). Many iron and steel goods sit in chapters 72 and 73, including some screws and bolts.

If your buyer lists a CN code, match it to your invoice. If not, ask them which codes they declare your goods under.

Step 3: Gather the documents you already have

For a typical aluminium extruder or steel processor, you'll need:

1. Fuel records for the period: natural gas, LPG, diesel or coal invoices for furnaces and heating.
2. Production records: tonnes produced of each product, and tonnes shipped to this buyer.
3. Purchase invoices for your raw metal (ingot, billet, slab, wire rod), with the supplier name and country of origin.
4. Scrap records: how much scrap you melted and where it came from.
5. Electricity bills. For aluminium and most steel goods, electricity isn't counted in the CBAM cost, but templates often still ask for it.

Step 4: Decide between actual data and default values

You can supply your actual emissions, or tell your buyer to use default values. Actual data is usually lower, but for the importer to use it in its declaration, it has to be verified by an accredited verifier. The first verification includes a site visit. We explain the trade-off in default values versus actual emissions.

Step 5: Fill in, check and send

Fill in the template, then check it the way your buyer will: do the totals add up, do the CN codes match your invoices, is the reporting period right, and is every assumption written down? Send it with a short covering note listing the documents you used. Keep a copy. Your buyer will ask again next year, and other EU customers will ask for the same data.

Common mistakes

• Counting electricity emissions in the total for aluminium or steel goods, where CBAM counts direct emissions only.
• Leaving out the emissions of the metal you bought in (precursors). For extruders and re-rollers, this is usually the biggest number.
• Reporting the whole factory's output instead of the specific product the buyer imports.
• Missing the buyer's internal deadline, which is often months before the EU deadline.

Frequently asked questions