A system for automatically forming stacks of cartons for feeding a magazine for supplying cartons to a packaging machine includes a primary support on which the stacks of cartons are formed, and a secondary support for temporarily receiving a series of the cartons thereon as a previously formed stack of cartons is removed from the primary support. The stack of cartons collected on the primary support is moved onto a transport conveyor for transport to a loader for the magazine for feeding into the packaging machine.