Abstract
The asymmetric unit of the title salt, C7H8N3 +·C7H5O6S-, comprises two 1,3-di-hydro-2H-benzimidazol-2-iminium cations and two 2-hy-droxy-5-sulfobenzoate anions (Z' = 2). In the crystal, the mol-ecules inter-act through N-H⋯O, O-H⋯O hydrogen bonds and C-O⋯π contacts. The hydrogen-bonding inter-actions lead to the formation of layers parallel to (01). Hirshfeld surface analysis revealed that H⋯H contacts contribute to most of the crystal packing with 38.9%, followed by H⋯O contacts with 36.2%.