In the mol-ecule of the title compound, 2C(4)H(10)N(3)O(2) (+)·SO(4) (-), the cations are planar (r.m.s. deviations = 0.0144 and 0.0236 Å) and oriented at a dihedral angle of 62.30 (4)°. Intra-molecular N-H⋯O hydrogen bonds result in the formation of two planar six-membered rings. The cations are linked to the sulfate ion through inter-molecular C-H⋯O and N-H⋯O hydrogen bonds, forming an R(2) (2)(8) ring motif. In the crystal structure, inter-molecular N-H⋯O and C-H⋯O hydrogen bonds link the mol-ecules into a three-dimensional network.