The asymmetric unit of the title compound, C4H8N4O2+·C4H7N4O+·SO42−·HSO4−, contains one half of an O—H...O hydrogen‐bonded dimer‐like unit, viz. a C4H8N4O2+·C4H7N4O+ unit and one half of an SO42−·HSO4− unit. Each of these dimeric units lies on an inversion centre, with the O‐bound H atoms disordered across inversion centres. The cations and part of the anions are arranged in layers parallel to the (20) plane through a combination of N—H...O, N—H...S and O—H...S hydrogen bonds