In the title compound, C9H11NO5S, the O=S=O plane of the sulfonyl group is twisted at a dihedral angle of 52.54 (16)° with respect to the benzene ring. The dihedral angle between the carb-oxy-lic acid group and the benzene ring is 49.91 (16)°. In the crystal, C-H⋯O, N-H⋯O and O-H⋯O hydrogen bonds link the mol-ecules into (001) sheets.
Keywords: O—H⋯O hydrogen bonds; benzenesulfonamido; crystal structure; propanoic acid; sulfonyl group.