In the title compound, C8H7NO3S, the benzene ring is oriented at a dihedral angle of 69.25 (7)° to the S and O atoms of the sulfonyl group. The heterocyclic ring approximates to an envelope, with the N atom in the flap position. In the crystal, mol­ecules are linked by N—H⋯Oc (c = carbon­yl) hydrogen bonds, forming C(5) chains along [001]. Two R 2 2(10) loops arise from pairs of C—H⋯O hydrogen bonds and a weak aromatic π–π stacking inter­action [centroid–centorid separation = 3.8404 (11) Å] also occurs.