Mail entering the United States from abroad first arrives at the Postal Service before any packages are sent to U.S. Customs for assessment of duties and taxes owed. Customs processing is required for all parcels, including those sent from overseas military postal facilities (APOs and FPOs). Work continues with the UPU, IPC, and U.S. Customs and Border Protection to streamline and improve these processes. The Postal Service is also supporting the introduction of advance manifesting requirements for mail shipments to improve security, deter criminal activity, and enhance the efficiency and speed of clearance operations.