Aminoiminomethane-sulfonic acids were prepared by the cathodic indirect oxidation of the corresponding thioureas using a pertungstate/tungstate redox mediator driven by H2O2 electrogenerated from O-2 at a cathode and by the anodic indirect oxidation using a Cl-2/Cl- redox mediator at an anode. Affecting factors for this kind of paired electrosynthesis, such as pH, temperature, current density, amount of charge passed, supporting electrolyte and electrode material were optimized for both the cathodic and anodic oxidations. The paired electrosynthesis was carried out in H-type and flow-type divided cells, and maximum current efficiencies of 136 and 142% could be obtained, respectively. Mechanism of the both indirect electrooxidations was also investigated.