An apparatus for encoding magnetic data and printing on a plurality of closely spaced labels releasably mounted on a supply roll of carrier strip, includes a magnetic head for encoding the labels and a printer for printing on the labels. The carrier strip extends from the supply roll past the magnetic head and to the printer, and forms a variably sized loop between the head and the printer. The variably sized loop has a gap, across which an encoded label may be transferred so that movement of a label past the printer is independent of movement of the supply roll. The magnetic head is movable parallel to the carrier strip so that the plurality of labels may be encoded and printed without reversing the supply roll, thus increasing the speed at which labels may be encoded and printed. The speed of the movable head may be precisely controlled to ensure accurate encoded. The encoded data is verified when the magnetic head moves over the label back to its original position.