Sodium percarbonate particles with a coating layer comprising sodium sulfate in the form of a high-temperature phase of sodium sulfate and/or of a high-temperature phase of a double salt of composition Na4(SO4)1+n(CO3)1−n where n is from 0 to 0.5 have an improved storage stability in detergent and cleaning composition formulations as compared with sodium percarbonate particles which comprise sodium sulfate in the coating layer only in the form of sodium sulfate (V) or burkeite.