In the structure of the title compound, [Co(4)(C(2)O(4))(PO(4))(2)(H(2)O)(2)](n), there are layers composed of the phosphate anions and two independent Co(II) cations. These layers are parallel to (001) and are bridged by the oxalate anions that are situated in special positions on centres of symmetry. One independent Co atom has an octa-hedral coordination, while the second independent Co atom is coordinated in a trigonal-bipyramidal coordination that includes the water mol-ecule. The crystal packing is stabilized by O-H⋯O hydrogen bonds between the coordinated water mol-ecules and oxalate O atoms.