Via a thoughtful analysis it is demonstrated that the mathematical problem of the voltammetry of a simple charge transfer process of any reversibility degree at a macrointerface is totally equivalent to those of the CE, EC and CEC mechanisms such that they all can be reduced to a formally identical one-variable problem. The simplicity and generality of the resulting boundary value problem makes it very easy and rapid the study of the response in any voltammetric technique by analytical or numerical methods.