In the crystal structure of the title compound, K+·C7H7ClNO2S−·H2O, the K+ ion is heptacoordinated by two O atoms from water molecules, four sulfonyl O atoms and the Cl atom of the anion. The S—N distance of 1.584 (3) Å is consistent with an S—N double bond. In the crystal, anions are connected by K+ cations into layers parallel to the ab plane. The water molecules are coordinated to the K+ cations and are additionally linked by intermolecular O—H⋯Cl and O—H⋯N hydrogen bonding
