AbstractHeavy alkylated benzene, which is accumulated as a by‐product from linear alkyl benzene synthesis, was evaluated as a starting material for anionic liquid sulphonate surfactants.Chemical structure analysis by GC/MS showed that the by‐product contains eight different paraffinic side‐chains, within the carbon range C12–C15. Accordingly, sulphonation conditions for it were adjusted to optimize the reaction yield and product quality.Liquid surfactant formulations based on these anionic sulphonates were established by incorporating other necessary ingredients. The formulations developed have shown high efficiency as detergents, wetting agents and emulsifiers.