Under the USSFTA, tariff preference is given based on importer's declaration. However, it is usually a commerical practice that the US importer will require the Singapore exporter to make some form of self-declaration of origin.

Under the USSFTA, the exporters, importers or manufacturers could apply for a written Advance Ruling from the customs authority on the origin of the good.

The relevant information, including the production records and cost statements should be submitted to the US Customs and Border Protection Bureau. A decision will be made by the US Customs within 120 days after all the submission of the information has been completed.