In the title compound, C(15)H(14)N(2)O(5)S, two similar mol-ecules comprise the asymmetric unit, which are linked by strong inter-molecular C-H⋯π inter-actions. Both mol-ecules are bent, with dihedral angles of 71.94 (16) and 74.62 (15)° between the benzene rings. An intra-molecular N-H⋯O hydrogen bond occurs in each mol-ecule. In the crystal, inter-molecular N-H⋯O and O-H⋯O hydrogen bonds link the mol-ecules into a three-dimensional network.