The present invention relates to a method for preparing phosphoramides having a glass transition temperature in one embodiment of at least about 0° C., in another embodiment of at least about 10° C., and in still another embodiment of at least about 20° C., the phosphoramides being substantially free of acidic, basic, or halide impurities, or their precursors. The invention also relates to resin compositions comprising at least one thermoplastic resin and at least one phosphoramide having a glass transition temperature of at least about 0° C., wherein the phosphoramide is prepared by the method of the invention.