Feeder apparatus for the automatic insertion of added yarn according to the present invention, of the type suitable for being installed on textile machines provided with at least one support creel for the bobbin of base yarn and automatic change of the spool of combined yarn, comprising at least one first and one second unit for feeding the added yarn, means for directing said added yarn and means for coupling the added yarn with the base yarn to form the combined yarn, characterised in that each unit for feeding the added yarn consists of a reel of added yarn placed on support means in contact with a motorised feed roller, in such a way that each feed unit is provided with its own feed roller and is independent from the others, and relative method.