The effect of electric potential on the lubricating adsorbed ionic films has been studied for a non-halogenated phosphonium orthoborate ionic liquid used as an additive in a biodegradable oil. A tribotronic system, designed around a ball-on-disc film thickness measurement system, was developed and manufactured in-house. This setup allowed for applying an electric potential between the test ball and a set of counter electrodes. The lubricating film thickness clearly decreased at negative potentials and increased at positive potentials. The trends suggested that the anions, acting as anchors on the surface, are instrumental in the formation of thick and robust lubricating ionic boundary films. The application of high positive potential, outside the electrochemical window, resulted in an enormous boost to film thickness, suggesting the formation of ionic multi-layers. The complementary neutron reflectance experiment showed electroresponse in the form of a change in thickness and the ionic composition of the boundary films.