Halogenated N-sulfamyl propionamidine addition salts corresponding to the formula ##STR1## are provided, in which X represents halogen and A represents an acid selected from sulfuric acid, nitric acid, benzenesulfonic acid; toluenesulfonic acid; 2,4,5-trichlorobenzenesulfonic acid; trichloroacetic acid; trifluoroacetic acid or methanesulfonic acid. They are useful as intermediates in the preparation of famotidine. They are prepared by reacting a halogenated propionitrile with the respective acid.