What happens if customs opens your package?
What happens if customs opens your package? The customs officials will examine the contents of the package to determine if any taxes, duties, or other fees are applicable. The package may also be inspected to ensure that it complies with all laws and regulations of the destination country.
How do customs know who to stop?
In the air passenger environment, air carriers transmit passenger information to CBP through the Advance Passenger Information System (APIS). CBP officers also rely on the Interagency Border Inspection System (IBIS) to determine which individuals to target for secondary examination upon arrival in the United States.