For products that are variations, all of the variations inherit the UPC Code value from the “parent” product. This is not correct. Each variation has its own UPC code.
CS-Cart exposes the UPC Code value on the General tab for each product variation, but if you try to change it, the UPC reverts back to the parent’s UPC code.
The same issue exists for Features assigned to the parent product, but the feature value might need to be different for each variation.
I am not sure where this field is coming from. I use AB Unitheme2 and a bunch of add-ons. It might be from the Avatax add-on. See the screen capture attached. Also, UPC_CODE is the last column in the cscart_products table.
In any case, the same value over-write issue happens with any Feature added to the Parent and variations.
As @thetool have correctly stated, there is no such field in the default CS-Cart Store Builder and Multi-Vendor, so you need to find out which of the third party add-ons installed in your store adds this field and then, contact its developers directly on this case.
