Transaction value as the primary basis for export valuation, with sequential fallback rules and a declaration rejection mechanism. Valuation of export goods uses transaction value as the primary basis; if not accepted valuation proceeds by sequential fallback rules. Exporters must file an Export Value Declaration, which may be rejected and redetermined through prescribed procedure. Consignments ordinarily should not be detained during enquiries, and assessing officers use notified exchange rates for currency conversion in arriving at export value.