United States border preclearance

United States border preclearance is the United States Department of Homeland Security's (DHS) practice of operating prescreening border control facilities at airports and other ports of departure located outside of the United States pursuant to agreements between the United States and host countries. Travelers are subject to immigration and customs inspections by Customs and Border Protection (CBP) officers before boarding their transportation onward to the United States.^[1] Preclearance applies to all passengers regardless of their nationality or purpose of travel. Upon arrival, precleared passengers arrive in the United States as domestic travelers, but may still be subject to re-inspection at the discretion of CBP. This process is intended to streamline border procedures, reduce congestion at American ports of entry, and facilitate travel into airports that otherwise lack immigration and customs processing facilities for commercial flights.

The history of inspecting U.S.-bound passengers in foreign countries began in 1894, when American immigration inspectors were deployed to sea ports in Canada. Modern preclearance facilities were first introduced in 1952 at Malton Airport (now Toronto Pearson International Airport) and Calgary International Airport under an informal arrangement with the government of Canada and are now available at eight major Canadian airports and one seaport, while several other seaports and one rail station in British Columbia have "pre-inspection" facilities for screening immigration admissibility only.^[2] Preclearance facilities also exist in airports in Aruba, the Bahamas, Bermuda, Ireland, and the United Arab Emirates.^[3][2]