Import of compressed gas cylinders requires a licence, pre arrival declaration and Customs permission before landing and release. Imports of cylinders filled or intended to be filled with compressed gas require a valid licence and pre arrival procedures: the ship's master or agent must give notice and deliver a Form A declaration to the pilot and Customs; importers must file a prior bill of entry with the licence and documents for assessment. Landing is permitted only with the Commissioner of Customs' permission after Preventive Customs verifies assessment and permissions; assessed bills showing licence and payment evidence must be produced before landing, and prompt removal after landing is required or enforcement action will follow.