The invention is directed to a process for multilayer coating of substrates which comprises a) applying a filler layer of a filler coating composition to a substrate, b) curing the resultant filler layer by irradiation with high energy radiation and c) applying a top coat layer to the cured filler layer and curing the top coat layer, whereby the filler coating composition comprises A) at least one binder capable of free-radical polymerization having fewer than three olefinic double bonds per molecule, B) at least one ester of alpha,beta-olefinically unsaturated monocarboxylic acids capable of free-radical polymerization having one olefinic double bond per molecule and C) at least one compound having at least one phosphoric acid group.