In the title compound, C(7)H(8)NO(4) (+)·Cl(-)·2H(2)O, the organic mol-ecule is almost planar with an r.m.s. deviation of 0.0164 Å for all non-H atoms. An S(6) ring motif is formed due to an intra-molecular O-H⋯O hydrogen bond. In the crystal, the mol-ecules are linked into a three-dimensional network by N-H⋯Cl, N-H⋯O, O-H⋯Cl and O-H⋯O hydrogen bonds.