The significance of the Frumkin correction at the liquid \ liquid interface is discussed critically. It is shown that it applies only at equilibrium, that is, in the absence of faradaic current. Instead, a correction introduced by Senda, the Levich correction, should be used if the system is not at the equilibrium. The magnitude and importance of the Levich correction is considered using a simplified model for the potential profile across the interfacial region. It is also suggested that due to the large potential drop in the organic phase diffuse double layer, the 'inner' layer potential difference, if such a quantity exists, is perhaps too small to allow the measurement of the potential dependence of ion transfer.