Your friendly Global store for UPC’s / EAN’s / GTIN’s.
And did we mention it should be your only store for them?
GS1 are the official globally recognised authority on barcodes. They manage the world’s database on them and who Amazon uses to validate if the barcode used for the product listing matches the Brand / company information. Other channels increasingly are using their API’s to validate barcodes and company information too.
GS1 has ambition to standardise data schema for barcode records.
Or to put it another way, only ever get barcodes from GS1. Like, always.