Aviation security screening, as part of the preclearance process, must be maintained at a level comparable with Transportation Security Administration (TSA) standards. This ensures security on U.S.-bound flights and allows passengers and their baggage to transfer to connecting flights in the United States without undergoing re- screening. Some foreign airports may already provide security screening at or near this level, but a signed Memorandum of Cooperation between TSA and the local General Civil Aviation Authority is required for preclearance operations.

Not all eligible flights departing from a preclearance airport must be precleared. As long as U.S. air carriers operating at the airport are provided equal access to preclearance service, airports may work with CBP to change the number and scheduling of precleared flights.

 Inflight Passport Control: Eligible passengers may complete administrative tasks that would otherwise be completed during the inspection process through the inflight seat-back entertainment system before their plane lands at the preclearance airport. This allows passengers to save time as they connect to a U.S.-bound flight.
 Examination of connecting baggage at the point of origin: Using BIWIS, baggage images and data, including x-ray images, could be collected and transmitted to CBP from a passengerÂ’s first point of departure. This could reduce the number of bags that must be imaged and screened at the preclearance airport and allow CBP to identify suspicious baggage earlier.