If you sell steel, aluminium, cement, fertilisers, hydrogen or electricity into the EU, your buyer now needs something from you that a sustainability report cannot provide: installation-level CBAM supplier data, calculated the EU’s way and ready for third-party verification.
Since 1 January 2026, the gap between supplying that data and not supplying it is no longer a paperwork problem. It is a price.
This blog explains what CBAM supplier data actually is, why it now sits directly on the cost line, and how importers and their suppliers can avoid being defaulted into the most expensive outcome.
What Is CBAM Supplier Data?
CBAM supplier data is the set of embedded emissions figures a producer must hand to its EU customer so that customer can report the carbon emissions embedded in imported goods to the European Commission. Under the EU Carbon Border Adjustment Mechanism, the carbon border adjustment mechanism puts a carbon price on carbon-intensive goods at the EU border, matching the carbon cost that EU producers already pay under the EU Emissions Trading System.
The detail that trips most suppliers up is what kind of data qualifies. CBAM will not accept most existing ESG or LCA figures as-is; they need to be recalculated at installation level using the EU’s CBAM methodology.
Generic greenhouse gas emissions figures, life-cycle assessments and product carbon footprints are built on industry averages and emission factors; CBAM requires installation-level emissions data, calculated for the specific facility where the goods were produced, using the EU’s monitoring and reporting methodology.
It covers both direct emissions from your production processes and, for some sectors, indirect emissions from electricity consumed. Think of it as the difference between an estimate and an audited number — only the audited number reduces what your buyer pays.
Why Supplier Data Now Drives Your CBAM Costs
For two years this was a reporting exercise. During the transitional period — 1 October 2023 to 31 December 2025 — EU importers filed quarterly reports and faced no carbon cost. That phase is over.
From 1 January 2026, EU CBAM entered its definitive period. Imports made in 2026 now create real financial liability, settled later through CBAM certificates whose price tracks the EU ETS carbon price.
Reporting also changes shape: instead of quarterly filings, importers submit annual CBAM declarations, with the first declaration covering 2026 imports due by 30 September 2027. Certificate sales begin in 2027, so no certificates are purchased in 2026 — but the emissions you report for 2026 set the bill.
This is why supplier data moved from the sustainability team’s desk to the finance team’s. Every tonne of reported embedded emissions is now a quantity an importer must eventually cover with purchased CBAM certificates. The quality of your emissions datais, in plain terms, a line item.
Actual Data vs Default Values: The Decision That Sets Your Exposure
When a supplier cannot provide verified actual data, the importer must fall back on default values published by the European Commission — and these are designed to hurt. Default values represent conservative, high-end assumptions for an exporting country and product, intended to push companies toward reporting actual emissions. For iron and steel, CBAM default values can be significantly higher than many producers’ real emissions intensity, especially for more efficient plants.
The penalty is deliberate and it grows. The Commission applies a mark-up on top of the default value, so the longer a supply chain leans on default data, the wider the gap to actual costs becomes under the CBAM rules. Unlike the transitional period, there is no explicit percentage cap on how much of a declaration can rely on default values, which means a supplier who stays silent can effectively set their buyer’s worst-case price.
Actual emissions data flips this. When a supplier provides verified emissions data showing genuine emissions intensity, the importer reports the real figure, surrenders fewer CBAM certificates, and pays less. The same shipment of steel can look carbon-intensive on default values and entirely manageable on actual data. For carbon-intensive goods, that delta is the single biggest lever a supplier holds over a buyer’s CBAM costs — and over its own competitiveness in the EU market.
What Makes Emissions Data Verification-Ready
Actual data only counts if it survives scrutiny. From 2026, supplier-specific emissions data used in a CBAM declaration is expected to be verified by an accredited third-party verifier; if verification is not obtained or is not successful, default values apply regardless of how good the underlying numbers were.
Verification is also where timelines bite. Verifiers typically use risk-based procedures that may include on-site visits to the facilities that produce CBAM goods, and they work through the supply chain based on materiality and verification planning rather than ad-hoc checks. Accredited capacity is limited, so suppliers that start late risk missing the window and being defaulted anyway.
To report embedded emissions that hold up, the data needs three things: clearly defined system boundaries, the right split between direct and, where required, indirect emissions for your sector, in line with CBAM rules for each product group, and a documented audit trail of inputs, calculations and evidence. CBAM requirements reward traceability — anything that cannot be explained will be rejected.
In practice that means keeping every reported figure linked to the document it came from, with validation applied as the data is captured rather than reconstructed months later under a verifier’s questions.
How to Approach CBAM Supplier Data Collection
Good data collection is a process, not an email. The importers managing this well treat it like a controlled close, not an annual scramble.
Start by mapping which imported goods are in scope by CN code, then trace each back to the installation and supplier responsible. Issue structured data requests using the EU’s standard communication template so the figures arrive in a format compatible with your CBAM declaration — free-form spreadsheets create reconciliation work and verification risk.
Vet every response for installation-level granularity, the correct methodology, and the production-route detail (and any raw materials or precursor emissions) the calculation depends on. Behind even a clean template sits messy evidence — invoices, utility bills, production logs and certificates in inconsistent formats — and the tools that scale here are the ones using OCR and language models to extract and structure that source material into installation-level records, rather than re-keying it by hand where errors and delays creep in.
Then plan for the suppliers who go quiet. A non-responding supplier is not a neutral outcome; it is a decision to accept default values and their mark-up.
Build a tiered follow-up, offer support or third-party help to suppliers that lack internal measurement capability, and flag early any supplier whose data gap will materially inflate your reported emissions.
Running a Supplier Assessment Across Your Supply Chain
You will not get verified data from every supplier in year one, so the question is where to spend the effort. The answer is almost always concentration: across most CBAM-exposed supply chains, a small share of products and suppliers accounts for the overwhelming majority of embedded carbon emissions. One retailer’s CBAM analysis found roughly 10% of in-scope products drove over 80% of relevant emissions, traced to a short list of suppliers.
That makes a CBAM supplier assessment a prioritisation exercise. Segment suppliers by emissions exposure and by their ability to deliver verification-ready data, then act on the high-impact, low-readiness corner first — through engagement, support, or, where a supplier cannot or will not move, by sourcing alternatives.
The same assessment doubles as procurement intelligence: It tells you which supplier relationships carry future CBAM costs and which give you a low-carbon advantage as the EU’s free allowances phase out through 2034 and the carbon price rises.
Managing EU CBAM Compliance at Scale
A single importer can face dozens or hundreds of suppliers across multiple CN codes, installations and reporting cycles, each needing structured, evidence-linked data on an annual schedule. The constraint is rarely intent — it is fragmented inputs, disconnected workflows, and figures that cannot be traced back to their source when a verifier asks.
A 2026 Verdantix analysis of enterprise carbon management software found AI differentiates most clearly in this environment when it targets specific bottlenecks — improving data quality, accelerating supplier engagement, and catching anomalies before they surface in an audit — rather than being deployed as a general-purpose layer across a platform.
This is the problem Credibl is built around to resolve: It pulls the invoices, utility bills, supplier inputs and disclosures behind a CBAM declaration into a single system of record, so every reported figure keeps its evidence and its audit trail. Its supplier-assessment and Scope 3 capabilities take on the parts that scale worst — chasing non-responsive suppliers, validating what they send back, and augmenting gaps from public disclosures where a supplier cannot yet measure its own emissions — while cost modelling lets finance see, in euros, what each data gap adds to the certificate bill. And because the same supplier data also feeds CSRD and IFRS S1/S2 reporting, it is collected once and used many times, not spent on CBAM alone.
None of this is software for its own sake. It is a defensible, repeatable path from scattered supplier inputs to a verification-ready declaration — one that still holds up when the verifier, and later the auditor, arrive.
Frequently Asked Questions
What happens if a supplier won’t provide emissions data for CBAM?
The importer must use the European Commission’s default values for that good. Because default values are deliberately conservative and carry a mark-up, this almost always raises reported emissions, the number of CBAM certificates required, and total cost.
Can ESG or LCA data be used for CBAM?
No. ESG reports, life-cycle assessments and product carbon footprints rely on averages and do not meet CBAM rules. CBAM needs installation-level emissions data for the specific facility, calculated with the EU methodology and prepared for verification.
Who verifies CBAM emissions data?
An accredited third-party verifier, operating under CBAM verification principles aligned with the EU ETS. Without that verification, actual emissions data cannot be used and default values apply instead.
Does CBAM apply if I import under 50 tonnes a year?
A de minimis exemption removes importers whose total net imports of CBAM goods stay below 50 tonnes per year — replacing the old €150 consignment threshold. The Commission estimates this exempts about 90% of importers while still covering 99% of embedded emissions. Hydrogen and electricity are excluded from the exemption.
Does the UK have its own CBAM?
Yes. A UK CBAM is scheduled to begin in 2027, so suppliers selling into both markets should expect parallel emissions data requests under separate rules.
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