No. The UPC barcode and 12-digit GTIN do the same job as an EAN barcode and 13-digit GTIN. UPC originated in the United States but is part of global GS1 standards. So if you license UPC from a GS1 organization, you have no problem using them globally. When a 13-digit number is required, you can add a zero at the beginning of your 12-digit GTIN.