A cover feeder for providing book covers to a production unit of a book completion line includes a first receiving device for book covers of the same format, which can be positioned individually, in an overlapping flow and/or in a stack thereon, and a second receiving device that is arranged upstream of the first receiving device for a stack of book covers having different formats. The cover feeder includes a control unit to which information can be transmitted relating to the format and sequence of book covers in the stack of book covers having different formats, and a laterally adjustable centering device connected to the control unit for a defined lateral displacement and/or aligning of respectively one book cover that is separated out from the second receiving device and is positioned on the first receiving device.