Provided herein is a process for isolating at least one (thio)phosphoric acid derivative, which has a boiling point of at least 70° C., from a product mixture including the at least one (thio)phosphoric acid derivative, at least one salt selected from ammonium salts and alkali metal chlorides, at least one polar solvent selected from the group consisting of ester solvents and ether solvents, and optionally at least one HCl scavenger; wherein the process is based on first dissolving the (thio)phosphoric acid derivative to be able to remove the at least one salt, and then causing solids formation of the (thio)phosphoric acid derivative.