A US Customs and Border Protection (CBP) preclearance facility at Toronto Billy Bishop City Centre opened on March 10, 2026, a key step for the expansion of transborder services to the United States by both Porter Airlines and Air Canada. Both airlines recently announced plans to expand such routes. Passengers who preclear US immigration at approved foreign airports are treated as domestic arrivals in the US, which allows airlines to launch flights to domestic terminals and airports without CBP facilities.