A method and a quaternary ammonium or phosphonium composition used therein for inhibiting retarding, mitigating, reducing, controlling and/or delaying formation of hydrocarbon hydrates or agglomerates of hydrates. The method may be applied to prevent or reduce or mitigate plugging of conduits, pipes, transfer lines, valves, and other places or equipment where hydrocarbon hydrate solids may form under the conditions. At least one quaternary ammonium or phosphonium compound is added into the process stream, where the compound may be mixed with another compound selected from other amino alcohols, esters, quaternary ammonium, phosphonium or sulphonium salts, betaines, amine oxides, amides, simple amine salts, and combinations thereof.