The asymmetric unit of the title compound, 2C2H6N5(+)·C4O4(2-), contains two 3,5-diamino-4H-1,2,4-triazolium cations and one squarate dianion. The squaric acid mol-ecule donated one H atom to each of the two 3,5-diamino-1,2,4-triazole mol-ecules at their N atoms. The squaric acid dianion has four C-O bonds which are shorter than a normal single C-O bond (1.426 Å) and are slightly longer than a normal C=O bond (1.23 Å), which indicates the degree of electron delocalization in the dianion. In the crystal, the cations and dianions are linked by N-H⋯N and N-H⋯O hydrogen bonds into a three-dimensional network.