Yes, when leaving the US, travelers typically go through customs at the airport or border crossing.
You go through customs when leaving the US before boarding your international flight.
When leaving the US, you go through customs at the airport before boarding your international flight.
Yes, travelers leaving the US typically go through customs at the airport before departing.
Yes, travelers leaving the US are required to go through customs at the airport before departing.
Yes, travelers leaving the US are required to go through customs and immigration checks before departing the country.
Yes, travelers leaving the US must go through customs at the departure airport before boarding their international flight.
Yes, travelers leaving the US are required to go through customs at the departure airport before boarding their international flight.
In the airport.
If you disembark your plane; yes.
If you are arriving from Puerto Rico in a country other than the United States, you must go through Customs. If you are arriving in a US airport from Puerto Rico, for instance, if you are arriving in Miami, or New York, or Los Angeles, you are on a domestic flight and will not be asked to go through Customs. If you started in Puerto Rico, you started from within the US. If you started from another country, you went through US Customs when you arrived in Puerto Rico.
it is very hard to go through UK customs
You go through customs when entering or leaving a country in Europe.