In the title molecular salt, C(2)H(4)N(3) (+)·C(7)H(5)Cl(2)O(3)S(-), C-C-S angle [112.25 (18)°] deviates slightly from that expected for ideal sp(3)-hybridization geometry. In the crystal, the components are linked by N-H⋯O and bifurcated N-H⋯(O,O) hydrogen bonds into chains parallel to [110].