600 & 601 Barcode Numbers
Barcode numbers that come from GS1 South Africa will either begin with 600 or 601. The only way to get legitimate barcode numbers like this is to go through GS1 South Afica, which means paying both a joining fee and annual membership fees to their organization. Many people do believe that the country of origin of the barcode numbers themselves corresponds with the country of origin of the product, however in reality products that come from South Africa can have any type of barcode on them and equally products manufactured in other countries, or even companies based outside of South Africa can obtain 600 and 601 barcodes through GS1 South Africa with ease.
This is a myth that is unfortunately fairly widespread. Please see this Snopes article on the origins of this myth as well as a thorough debunking of it.
All barcodes and barcode systems are designed for international use, so there are virtually no restrictions based on the country of origin world wide. Any specific examples of stores placing any type of restrictions on barcodes can be seen here.