For importers of CBAM-covered goods, the most impactful way to reduce your CBAM certificate costs is to use actual production emissions data from your non-EU suppliers rather than EU default values. Default values are set conservatively high — actual emissions from well-operated facilities are typically lower, sometimes significantly so.

But collecting verified supplier emissions data is not straightforward. This guide explains what data you need, how to collect it, and how to ensure it meets EU requirements for CBAM compliance.

Why supplier data matters for CBAM

CBAM certificate costs are proportional to embedded emissions. Default EU values assume worst-case production practices for each sector and country of origin. If your suppliers operate with lower emissions — through modern equipment, energy efficiency, or cleaner energy sources — using actual data can materially reduce your CBAM exposure.

For an example of how default vs. actual data affects cost, see our guide on CBAM reporting requirements and our CBAM cost calculation guide with examples.

What data EU rules require from suppliers

To use actual embedded emissions in your CBAM declaration, your supplier must provide:

• Direct emissions: GHG emissions from the production process itself (combustion, process emissions)
• Indirect emissions: For some goods (aluminium, steel), emissions from electricity consumption in production must also be included
• Production volume: Total output so emissions can be expressed per tonne of good
• Methodology documentation: How emissions were calculated, what emission factors were used, and what assumptions were made
• Third-party verification: The data must be verified by an EU-accredited verifier

The verification requirement

This is the critical step: actual emissions data used for CBAM must be verified by an accredited third-party verifier recognized under EU regulations. Without this verification, actual data cannot be used in CBAM declarations, and you fall back to default values.

Finding accredited verifiers with experience in specific sectors and countries of origin can be challenging, particularly for suppliers in countries where CBAM compliance is new. Start this process early.

Step-by-step approach to CBAM supplier data collection

1. Identify priority suppliers: Focus first on your highest-volume or highest-emission suppliers where the cost impact of switching from default to actual values is greatest
2. Assess supplier readiness: Determine which suppliers already calculate and track production emissions and which will need support
3. Send structured data requests: Provide clear templates specifying exactly what calculation methodology to use and what documentation to provide
4. Connect suppliers with accredited verifiers: Help suppliers find and engage verifiers who can certify their data for CBAM purposes
5. Validate incoming data: Review supplier submissions for completeness, consistency, and alignment with the EU methodology before submitting in your CBAM declaration
6. Build a data management system: Track which suppliers have provided verified data, when it was last updated, and which declarations it has been used for

Common challenges

• Suppliers unfamiliar with EU CBAM requirements or methodology
• Language barriers in supplier communication
• Limited availability of accredited verifiers in supplier countries
• Suppliers unwilling to share detailed production data for confidentiality reasons
• Data arriving too late for timely CBAM declarations

How Coolset supports CBAM supplier data collection

Coolset’s CBAM module provides structured supplier data request workflows, template documentation, and a supplier portal for data submission. The platform tracks supplier response rates and validates incoming data against the required CBAM methodology. Book a demo to see how it works.