A steady-stale model describing photofacilitated transport in liquid membranes is presented. The model can be used to consider photoactive carriers with a wide range of thermodynamic and kinetic properties in order to calculate photoinduced transport of solutes down their concentration gradient (photomodulation) and against their concentration gradient (photopumping). The description of transport in these systems is generalized by combining the relevant physical constants (diffusion coefficients, rate constants, concentrations, molar absorptivities, light intensity, etc.) into dimensionless parameters. Detailed descriptions of photomodulation and photopumping are presented for the case where the carrier has properties that are optimal for downhill transport in the dark (thermal transport). Absorption of light by the carrier and carrier solute complex can cause downhill transport to increase by 50% or to decrease by a factor of 4 depending on the light intensity. Photopumping can be maintained against a 10-fold concentration gradient, The transport efficiencies for photomodulation and photopumping are also discussed.