The title compound, C(14)H(10)Cl(4)O(4)S, is an inter-mediate in the synthesis of the PCB sulfate monoester of 4'-chloro-biphenyl-4-ol. Both the sulfate monoester and 4'-chloro-biphenyl-4-ol are metabolites of PCB 3 (4-chloro-biphen-yl). There are two mol-ecules with different conformations in the asymmetric unit. The solid state dihedral angles between the benzene rings are 18.52 (10) and 41.84 (16)° in the two mol-ecules, whereas the dihedral angles between the least-squares plane of the sulfated benzene ring and O-S (Ar-C-O-S) are 66.2 (3) and 89.3 (3)°. The crystal was an inversion twin with a refined component fraction of 0.44 (7).