Barcodes are commercially available via several suppliers.
Note : the pricing per label can vary based on the number of barcodes ordered
BibioTECH can handle a variety of barcode formats. Therefore, when purchasing additional barcodes, it is probably better to purchase barcodes in the same format as your existing ones. Just ensure you do not purchase duplicates of existing barcodes. Most barcode suppliers will check this with you.
However, if you cannot locate the same barcode format or you have no barcodes, then the recommended format for BiblioTECH barcodes is a plain 12-digit barcode
One company that supplies many libraries is ABcorp. Their 12-digit barcodes can be purchased via http://barcodes.abnote.com.au/public-library/12-digits/12-digits-43x16