One of the principal purposes of transport characterization is obtaining input information for a predictive modelling of membrane performance. To be able to fit the model parameters in a unique way for a given feed composition, additional measurements other than single salt rejections are needed. The recent progress in the development of corresponding experimental and theoretical approaches is outlined. These novel approaches to the transport characterization of active layers of NF membranes are presented: chronopotentiometry of membrane potential after a concentration step, pressure switch-off, and current switch-off, voltammetry of NF membranes, NF of trace ions and dominant single salts within a wide pressure range.