A duty-free shop works under the same system. The goods must be exported intact (they cannot be consumed in the country of sale), and they are importing into the destination country under that country's own tax rules. In some countries, in order to ensure that goods are exported intact, they are hand-delivered in a closed bag to the passenger at the gate after their ticket is scanned. In the United States, duty-free shops are technically considered class 9 Bonded Warehouses with regard to the U.S. Customs & Border Protection: