The FuelEU Maritime Regulation and the EU ETS both rely heavily on fuel-level data to determine compliance and reward the uptake of sustainable fuels. Yet as shipping companies begin to implement these requirements, one of the most pressing questions is practical: how should a shipping company demonstrate that a delivered fuel complies with the GHG intensity thresholds or even qualifies as a renewable fuel of non-biological origin (RFNBO)? Proof of Sustainability (PoS) and Pr
