4-Methyl­anilinium 3-carb­oxy-4-hy­droxy­benzene­sulfonate

In the title mol­ecular salt, C7H10N+·C7H5O6S−, the anion is deprotonated at the hy­droxy O atom of the sulfonate group. In the anion, an intra-ionic O—H⋯O hydrogen bond generates an S(6) graph-set motif. In the crystal, the inter-ionic N—H⋯O and O—H⋯O hydrogen bonds generate an R24(12) ring-set motif, linking the anions and cations into an infinite three-dimensional framework. The crystal structure also features C—H⋯π and π–π [centroid-to-centroid distance = 3.5946 (11) A] inter­actions.