CBAM phase three turns carbon data from a voluntary disclosure into a customs precondition. The rule boils down to two points: the embedded emissions an importer files must be verified by an accredited third party, and the data chain must be traceable and auditable (MRV—monitoring, reporting, verification). The old practice of clearing customs with a spreadsheet estimate stops working after October.

The direct hit on SNSUC clients lands at the tail of the transshipment chain. Take bitumen bound for the EU: without an on-chain carbon footprint record attached, the importer stalls at the CBAM pre-declaration stage, and the cleared cost runs well above a compliant cargo (the 3.2% FOB premium on equivalent-grade bitumen today is mostly carbon-compliance, not freight or quality). This is not a tariff—it is the delay and remediation cost of missing data.

Our answer is to write the carbon accounting result straight onto a SHA-256 chain: every emission segment—feedstock, refinery, ocean freight, loading—generates a hash and is fixed on ledger, so an accredited verifier reads the chain and issues an ISO 14067 statement. The importer receives click-to-verify carbon data instead of a signed letter. USD/CNY rose 0.0865 today and the RMB weakened, but the carbon premium is already baked into the dollar quote, so FX no longer erodes this margin in isolation.

Three moves for transshipment desks: first, October new orders must travel with a carbon record attached—do not wait for a customs bounce; second, if you are locking delivery three months out, sign the carbon-data sharing agreement now, or the chain cannot mint your MRV node; third, sulfur-heavy grades like Urals and Basrah Light carry higher emission factors, so run the sensitivity early instead of discovering at filing time that carbon cost ate the whole margin.