Methods for filling prescriptions in a customer order. Each of the products (12) is marked with a product barcode (24) containing information relating to a contained pharmaceutical. Prior to loading into a machine (10), each of the products (12) is free of markings relating to patient prescriptions in the customer order. The method includes using the machine (10) to read the product barcode (24) on each of the products (12) loaded into the machine (10). In response to reading the product barcode (24) on each of the products (12), at least some of the products (12) are labeled with information, such as a patient barcode (34), on a patient label (32) relating to a respective one of the prescriptions.