London Heathrow Airport

Coming soon: More pre-clearance

On a typical return flight from a trip outside the United States, you go to your departure airport, go through local security and immigration lines, hang around for your flight, arrive in the U.S., and go through U.S. customs and immigration lines before you can head for home or a catch domestic connecting flight. Although that's the typical pattern, it isn't the only pattern. Currently, at a few foreign airports, you can pass through local U.S. customs and immigration pre-clearance before you leave, so when you arrive back in the U.S., you arrive as a domestic passenger: Just pick up your baggage and go; no lines or passport stamping. And the Department of Homeland Security is pushing...