Step 1: Find out what is the preferential rate offered for your product
Step 2: Find out your product's rules of origin
Rules of origin are a set of criteria which determine a product's originating status in each respective FTA. It is put in place to ensure that only goods originating from the FTA partner countries will benefit from tariff concessions.
For Singapore-originating goods, an importer would have to prove that the goods are of Singapore origin via the presentation of a certification of origin in order to claim preferential tariffs on the goods in question. The Singapore exporter or producer can make this certification of origin on the export invoice without the need for a formal certificate of origin.