Complex collection efficiency in channel electrodes was revisited using numerical methods. This method has practical application when one wants to measure collection efficiency in systems where a side reaction unresponsive to the ac perturbation dominates the response. For complex collection efficiency to be applied experimentally, deviations from the purely diffusion limited reactions should be investigated. Three cases were modeled in this work: ideal case; EC reaction (coupling with a homogeneous chemical reaction); and linear kinetics at the detection electrode. From the modeling, an experimental framework and interpretation method was established that allows for the identification of the type of non-ideality and possible quantification of kinetic parameters. The ideal case was demonstrated experimentally using a microfluidic cell produced in-house.