If I leave Vienna, but have a layover somewhere else in Europe, what is the minimum amount of time I need on the layover? Don't I have to go through customs (or whatever it is called) at the last stop in Europe before returning to the US? If I remember that correctly, how much time should I allow for that - which would determine how long of a layover I need. Any suggestions would be appreciated to help me understand the process and time needed as I look for a return flight. Thanks!
It depends on what the final stop is - different airports have varying minimum connection times. Generally speaking I like having 2 hours at least
How long is a piece of string?
You won't need to go through customs as a connecting passenger, you will go through a passport check when you leave the Schengen area. And if you connect in the UK, you will need to go through a security check.
Customs is for when you get back to the USA. Unless you’re bringing back mass quantities of commercial merchandise for resale, or high-value purchases, it’ll be an almost non-event. US Border Patrol wants to know that you aren’t bringing back plants or raw meat, or a huge amount of money.
As for your layover, if you airline has booked you on to their connecting flight, they’ve determined that you should have sufficient time. An hour and a half or maybe two hours is probably plenty, depending on which airport. And, unless you’re planning on shopping or having a big meal at the airport, that won’t add to the time you’ll need.
if you go via Dublin you will be pre-checked there by US Customs and that could take a little while. Other places, no.
Let's make this easy. .where are you stopping after Vienna?
US Border Patrol wants to know that you aren’t bringing back plants or raw meat, or a huge amount of money.
US Border Patrol is not the agency you deal with at the airport. That's Customs and Border Protection (CBP). They want to know what you are bringing back.
but have a layover somewhere else in Europe,
How much time you need in Vienna to get to your plane from the front door of the airport, is very much dependent on where that "somewhere else in Europe" is.
If your Vienna-US is a single ticket, the airline has already figured out how much time you need at that "somewhere else in Europe' stop.
That makes the question that needs to be addressed: "When should I arrive at the Vienna airport?"
3 hours .......
US Border Patrol is not the agency you deal with at the airport. That's Customs and Border Protection (CBP)
… OK, so the Border Patrol is an agency under the Customs and Border Protection agency, which, in turn, is an agency of the United States Department of Homeland Security. Border Control, Border Protection … Either way, there’s a U.S. Border official in a uniform to encounter at the airport.
Arrive 3 hours before flight and have 3 hours for your layover.