The Cologne Higher Regional Court ruled that Lufthansa cannot advertise that customers directly reduce flight-related CO2 emissions during booking via sustainable aviation fuels, as the fuel is injected only after payment completion. The court partially rejected Lufthansa’s appeal, upholding Deutsche Umwelthilfe’s lawsuit that the claim misleads consumers about the timing of bio-kerosene injection into the system. Operators must now revise SAF marketing strategies to avoid regulatory bans on unsubstantiated “direct reduction” phrasing. This landmark decision sets a precedent requiring precise timing data for fuel injection claims in aviation advertising, preventing greenwashing that influences booking behavior under false pretenses.