A barcode reseller purchases barcodes in bulk to be sold for a one-off cost to individuals for use on products. The numbers they buy are now outside of GS1’s control and can be bought and sold without license fees etc. This means that they are much cheaper than other barcodes.
Warning signs of barcode resellers:
While many resellers are legitimate, some are not. Watch out for companies that: Are hard to contact, Cannot produce good evidence for the origin of their barcodes, sell barcodes extremely cheaply, and haven’t been established long (i.e. they could disappear at any stage).