The EU Carbon Border Adjustment Mechanism entered its definitive levy period in 2026, requiring importers to pay carbon costs on embedded emissions. For grades transshipped via SNSUC — fuel oil, bitumen, base oil and others — scrutiny shifts from annual filing to verifiable per-batch product carbon footprint. SNSUC anchors each cargo's title with a browser-side SHA-256 fingerprint, letting embedded-emission data be independently recomputed and mutually recognised across borders.