Southeast European exporters that source the same precursor from multiple suppliers need to ensure that emissions figures reported to EU customers reflect actual material consumption rather than the most favourable supplier data. Under the applicable calculation methodology, buying lower-emission inputs does not automatically allow a manufacturer to assign their emissions profile exclusively to selected export orders.
The issue is most acute for factories using shared inventories and production lines to serve several markets. A sales team may commit to supplying an EU customer with products made from lower-emission material, but the claim must be supported by records showing which inputs entered the relevant production process. Commercial agreements alone cannot demonstrate physical material use.
Weighted averages and evidence requirements
The definitive methodology generally requires a weighted average for suppliers of the same precursor type, subject to applicable reporting-period rules. More specific attribution may be possible where sufficient evidence establishes that particular material was used in the production process concerned. Material movements, inventory records and consumption data therefore play a central role in substantiating emissions calculations.
A simplified example shows how the approach works. A plant consumes 600 tonnes of precursor with an emissions intensity of 2.0 tonnes of CO₂e per tonne and another 400 tonnes at 0.5 tonnes of CO₂e per tonne. The resulting quantity-weighted intensity is 1.4 tonnes of CO₂e per tonne.
The calculation covers precursor input only, before processing emissions and any other applicable methodological requirements. The plant cannot use the lower figure of 0.5 tonnes of CO₂e per tonne for selected customer orders simply because the sales team wants to offer a more favourable emissions profile. The relevant calculation should follow consumed quantities and an established inventory method.
Purchase volumes do not necessarily match production consumption during the same reporting period, particularly when stocks change significantly. For example, a supplier delivering material in late December could account for a substantial share of closing inventory while contributing little to production during that year. Companies should reconcile purchasing records with stock movements and actual use before finalising the average.
Separate attribution where process arrangements support it
More specific attribution can offer commercial advantages when factory operating arrangements support it. A production process might receive material through a dedicated storage area, with a documented procedure controlling its release for use. Whether this supports a separate emissions claim depends on the material actually consumed and the applicable rules for defining process boundaries.
Manufacturers should assess such arrangements with their verifier before making product-specific commitments to customers. Technical differences between production routes do not, by themselves, establish that separate emissions figures are permissible. Engineers and commercial teams need to agree on the calculation structure allowed by the relevant methodology before marketing distinct product intensities.
Physical segregation also carries operational costs, including dedicated storage, additional material identifiers and revised production schedules. Smaller batches may reduce efficiency or increase changeover times. Exporters are expected to weigh these costs against expected commercial benefits rather than assume that more granular attribution will always deliver better outcomes.
A consistently documented and defensible average may be more practical than a complex segregation system that employees cannot reliably maintain.
Supplier documentation quality and customer-facing statements
The quality of information received from suppliers can materially influence the calculated average. One supplier may provide actual verified emissions values, while another requires use of applicable default values, with each contribution treated according to the relevant methodology.
Excluding a poorly documented supplier’s material from the calculation while continuing to use that material in production would misrepresent the actual input mix. Companies should instead quantify the supplier’s contribution and determine how it affects resulting emissions intensity.
Procurement teams can use this information to assess whether reducing dependence on suppliers with weak emissions documentation would improve their position. The effect depends on volume sourced: a small supplier may have limited influence, while a major source can shape the emissions profile of an entire process.
Management should calculate potential benefit from replacing each supplier and compare it with purchasing price, material quality and delivery constraints. The resulting sourcing strategy may differ from a simple ranking based exclusively on reported emissions intensity.
Linking CBAM claims to reporting periods and operational records
Emissions statements supplied to customers should clearly identify the relevant process boundary and reporting period. A process-wide average must not be presented as though it were an independently measured emissions value for every individual item. Buyers also need to understand that reported figures may change as the annual mix of consumed inputs changes.
Long-term supply agreements add uncertainty because final supplier mix may remain uncertain when prices are negotiated. Processors may use provisional scenarios and subsequently reconcile them against verified results if contractual arrangements permit this approach. Agreements should identify purchasing assumptions behind an initial figure and specify circumstances requiring an update.
Internal controls should connect customer-facing promises to purchasing, warehousing and manufacturing plans. When a salesperson proposes specific attribution to an EU customer, production and warehouse managers should confirm that it can be implemented and documented, while finance evaluates associated costs. Without coordination, a company risks promising a service that appears in contracts but cannot be demonstrated through operational records.
Updating assumptions when supplier mixes change
Management should review emissions assumptions whenever a major supplier changes rather than waiting for an annual verified figure. A provisional internal calculation can indicate whether a procurement change materially affects assumptions used to price new orders.
Such calculations should be labelled provisional and reflect evidence status for each input. This allows sales teams to adjust expectations without presenting an estimate as a verified result. It also makes potential impact of emergency purchases visible before effects accumulate over several months.
For Southeast European exporters, the commercial objective is to establish a sourcing and production arrangement that remains workable throughout the year. The strongest approach is not necessarily the most elaborate attribution system, but one that produces an emissions statement consistent with actual material consumption—even when the resulting average is less favourable than the lowest intensity quoted by an individual supplier.