Originally Posted by
jsloan
Or, for certain airports, if the passenger is making an international-to-international connection -- so be careful if trying to do HCT on a ticket through to another country.
Also, there was a pilot program operating this summer at IAD that sent connecting bags from certain flights through customs without having them reclaimed first. It's not currently operating, but it could be reintroduced at any time.
The other gotcha for IAD is that if you have a checked bag, you have to clear immigration/customs in the basement of terminal C, not the main terminal. There is no way out of the airport with your checked luggage from there. You have to recheck it and then clear TSA security into terminal C. If you have no checked luggage, you can go to the main terminal.