In the title compound, C(3)H(8)N(6) (2+)·SO(4) (2-), the melaminium cations and sulfate anions are inter-connected by N-H⋯N and N-H⋯O hydrogen bonds, forming a layer in the (101) plane. The layers are connected through multiple hydrogen bonds and π-π stacking inter-actions (centroid-centroid distance of about 3.4 Å).