The usual description of ion transport in membrane channels is based on dual model describing the channel conductance as the addition of bulk and surface contributions. This vision constitutes an idealization that it is extremely useful for modelling purposes. However, there are no surface- and bulk-labelled counterions in real solutions, but only ions that due to thermal agitation continuously interchange their role. Furthermore, ion transport in confined geometries may differ significantly from that in bulk conditions. Besides direct electrostatic interactions between the permeating ions and pore charges, other phenomena like interfacial access resistance or entropic effects due to obstacles and irregularities of the boundaries may play a role. We investigate here the limitations of the abovementioned two-state model by assessing experimentally the scaling behavior of channel conductance (G) with salt concentration (c) in structurally different protein and proteolipidic pores. Previous studies in both nanochannels have suggested a power law dependence G ∼ cα, where α is an exponent that has been reported to attain a variety of values depending of the system and the concentration regime. We hypothesize here that scaling exponents found in a specific system arise from a particular interplay between bulk and surface effects, being the distinction between them so subtle that the two-state model faints. In the case of biological pores, we show also that the presence of interfacial effects could give rise to an apparent universal scaling that does not reflect the channel actual characteristics.