Do You Have To Go Through Customs During A Layover? Customs and immigration are usually required at the connecting airport for international flights. You don't always have to for domestic flights. In most cases, passengers on layover flights must clear customs and immigration at the first point of entry.

Yes, in almost all cases, you must go through U.S. Customs and Border Protection (CBP) when connecting from an international flight to another flight in the United States, even if your final destination is in a third country. The U.S. does not have a "sterile transit" area like many European or Asian airports. This means that upon landing, you must clear immigration, collect any checked luggage (even if it is tagged through to your final destination), and then pass through customs. After clearing customs, you will typically find a "Baggage Re-check" counter immediately outside the customs hall where you can drop your bags back into the system. You must then pass through a TSA security screening to enter the domestic departures terminal. There is one major exception: if you are flying from an airport with U.S. Preclearance (such as Dublin, Shannon, or many major Canadian airports), you will clear U.S. customs at your departure city and arrive in the U.S. as a "domestic" passenger, allowing you to walk directly to your next gate without seeing a customs officer.