Compliance is non-negotiable for customs clearance. For the US market, ensure the engine is EPA or CARB certified. For the European market, look for CE marking, GS certification, and Euro V emission standards. Additionally, the unit should meet ISO 8528 standards for reciprocating internal combustion engine-driven alternating current generating sets. Always request Noise Level Certification (LwA), especially if the units are intended for residential or camping use, where levels should ideally be below 65dB at 7 meters.