The asymmetric unit of the title molecular salt, C6H10N22+·2H2PO3−, contains half of a benzene-1,2-diaminium cation and a phosphite anion, the complete cation being generated by a crystallographic mirror plane. In the crystal, N—H...O hydrogen bonds generate R22(9) and R22(8) ring motifs and O—H...O hydrogen bonds generate an R22(8) ring motif. Overall, these generate a three-dimensional framework. The crystal structure also features π–π interactions [centroid-to-centroid distance = 3.8642 (7) Å].