There seems to be some confusion about barcodes. Just as a brief explanation.

A barcode is a printed piece of information that is easy for a scanner to read. What people do with the barcodes is up to them. They are commonly used to hold product codes. In general retail, there is a set of standards that most but not e.g. Amazon follow. The most common barcode in use in Australia for retail is EAN-13. Since most large retailers in Australia follow this standard if a supplier wants their product sold by these large retailers they must put on them an EAN-13 barcode. The official recommendation is that this barcode is placed in the lower right at the rear of the item.

Since the barcode is put on by the manufacturer of the article, what often happens is that if a supplier changes to a different manufacturer, the barcode changes. That is why we have to send out so many scripts.