I don't know why, but I cannot login to eBay developer forum so that I am here to post a question about eBay API.
I am trying to look up a product by using UPC code with findItemsByProduct resource.
According to the official website (http://developer.ebay.com/DevZone/finding/CallRef/findItemsByProduct.html),
UPC—The UPC value for products in Music (e.g., CDs), DVD and Movie, and Video Game categories (or domains). If you know a product's UPC number, you can use this value instead of the eBay Reference ID to search for that product.
Does this mean that we cannot look up Electronic products (e.g. laptop), using UPC code? Actually, I have never seen yet any electronic products I could retrieve with UPC lookup.
Regards
As long as a seller has entered a UPC when the item was listed it should be possible to find it via the API. However, entering a UPC is not supported by all categories. To determine if a category supports UPC you can call GetCategoryFeatures and check that the UPCIdentifierEnabled field is true.
Since calling GetCategoryFeatues on the US site (ID 0) for the category Computers/Tablets & Networking > Laptops & Netbooks > PC Laptops & Netbooks (ID 177) returns true in the UPCIdentifierEnabled field you should be able to search for laptops via UPC.
Beware that UPC is not used in all countries. For example European countries use EAN (European Article Number) instead. If you are searching on those sites you will need to check the value of the EANIdentifierEnabled field when calling GetCategoryFeatures.