A theoretical study of the mechanism of the isomerization reaction HOC(+) --> HCO(+) is presented. The mechanism was studied in terms of reaction force, chemical potential, reaction electronic flux (REF), and bond orders. It has been found that the evolution of changes in REF along the intrinsic reaction coordinate can be explained in terms of bond orders. The energetic lowering of the hydrogen assisted (catalyzed) reaction has been identified as being due to the stabilization of the H(3)(+) transition state complex and the stepwise bond dissociation and formation of the H-O and H-C bonds, respectively.