Southeast European exporters that source the same precursor from multiple suppliers need to ensure that CBAM 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 particularly relevant 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 based on supplier precursor types
The definitive approach 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 shows 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 illustrates the effect on calculated intensity. 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.
This 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 a sales team wants to offer a more favourable emissions profile.
Consumption tracking and inventory reconciliation
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. Companies should reconcile purchasing records with stock movements and actual use before finalising the average.
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. This means closing stock can reflect deliveries that were not actually consumed within the same reporting period as production activity.
Separate attribution where process boundaries are supported
More specific attribution can offer commercial advantages when 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 involves operational costs, including dedicated storage, additional material identifiers and revised production schedules. Smaller batches may reduce efficiency or increase changeover times. Exporters should 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 averaging outcomes
Information quality from suppliers can materially influence the calculated average. One supplier may provide actual verified emissions values, while another requires use of applicable default values. Each contribution must receive the treatment required by 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 that 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 sourcing volume: a small supplier may have limited influence, while a major source can shape the emissions profile of an entire process.
Aligning customer statements with reporting periods
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 complexity because the 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 link customer-facing promises to purchasing, warehousing and manufacturing plans. When sales propose 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 cannot be demonstrated through operational records.
Updating assumptions when major suppliers change
Management should review emissions assumptions when 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, and it makes potential impacts 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 using 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.