sentences:  Pre-shipment inspection (PSI) agencies are companies that carry out physical inspection of the cargo and certify the value of the consignment after verification of the declared price against the ruling international price.Then the Customs authorities calculate the leviable of amount of duties and taxes on the basis of that certified value.This essentially has shifted the critical task of tax assessment to the PSI companies from the Customs inspectors and appraisers who were supposed to ascertain the assessable value of a consignment in accordance with the GATT valuation code.