What emissions data to collect from your suppliers before 2027

Why this is the money-saving step

As the default versus actual guide explains, defaults carry a mark-up so they are never cheaper than verified data. Where your producer is cleaner than the benchmark, actual verified emissions lower your charge. But you cannot conjure verified data after the fact: it depends on the producer's own records and an independent check, both of which take time. Start collecting now and you have a choice at return time; leave it and you are stuck on the expensive default.

The checklist to send your suppliers

Ask each supplier or producer of your CBAM goods for the following, per good and per production site:

• Production route. How the good was made (for example, the specific steel-making or aluminium-smelting route), because emissions intensity varies enormously by route.
• Verified embodied emissions per tonne (tCO2e/t). The actual embedded emissions of the goods, expressed per tonne, covering the emissions CBAM requires (direct emissions now; indirect Scope 2 emissions are out of scope until 2029 at the earliest, so confirm what is included).
• The verification body. Who independently verified the figures, and to what standard. Unverified producer numbers on a spreadsheet will not carry the same weight as independently checked data.
• Any overseas carbon price already paid. Whether the goods were subject to an ETS or carbon tax abroad, the amount, and documentary evidence, because that supports overseas carbon price relief against your UK CBAM liability.
• Coverage and dates. The period the data covers and confirmation it applies to the specific goods you import, so it maps to your consignments.

How to run the collection

Treat it as a procurement task with a deadline, not a one-off email:

1. Map your suppliers to your CBAM goods. List which suppliers provide which in-scope goods, so you know who to chase.
2. Send a standard request. One clear request covering the checklist above, so every supplier gets the same ask and you can compare responses.
3. Give them lead time. Producers may need to commission verification. Asking in good time before 1 January 2027 is the difference between having the data and not.
4. Store it against the goods. Keep the verified figures and evidence filed by good and consignment, ready for your first return in 2028.

What the data feeds into

Once you have verified emissions per tonne, they slot straight into the charge calculation: emissions per tonne times your tonnage gives embodied emissions, which times the rate gives the gross charge, before overseas relief. See the charge calculation guide for the full formula, and the key dates guide for when it is all due.

Frequently asked questions

Sources

• GOV.UK, Introduction of the Carbon Border Adjustment Mechanism, on using actual verified emissions data, overseas carbon price relief, and Scope 2 emissions being out of scope until 2029. gov.uk
• GOV.UK, CBAM Policy Summary, on the default-versus-actual choice and the evidence needed for overseas carbon price relief. gov.uk

Content current as of 12 July 2026. The verification and reporting mechanics sit in secondary legislation being finalised in 2026; confirm the detailed data requirements against the enacted rules and HMRC guidance before you rely on them.