Abstract: A method for using a POS printer that includes means for magnetizing and reading the ON-US and ROUTING information from preprinted magnetic characters on a check. The characters are printed with an ink having magnetizable particles embedded therein. First, the ROUTING and ON-US fields of the check are magnetized, either by a fixed magnet, or within the read head itself. Next, the characters within the ROUTING and ON-US fields are read by the read head, and the signals analyzed by the electronics of the POS printer. This is followed by a verification, in which the printer electronically verifies that the account is not a "bad" account. If the account is good, the printer continues to endorse the check on its back and/or encode the check by printing MICR characters in the AMOUNT field on the face of the check. The POS printer may magnetize and read these characters after they are printed, in order to verify that the correct amount has been encoded onto the check.