go through custom for layover in Rome or airside from Barcelona to Palermo?

Barcelona is in Spain, Rome and Palermo are in Italy. Both are members of the EU so no customs, and both are members of the Schengen Agreement, so no passport check. Just like changing planes in Chicago going from St Louis to Green Bay.

Does it mean that i go through customs in Palermo, the destination and not in Rome? THank you for giving me peace of mind.

No, there are no customs unless you are coming directly from outside the EU. You said you were beginning your trip in Barcelona. Is that true, are you starting in Barcelona, or are you starting from somewhere else?

Sally, You never go through customs, your bags do. Customs is the check on goods, the contents of your cases. This is a random check only, takes zero time and occurs wherever you pick up your bags. And no customs between EU countries anyway. Forget customs.

Immigration (aka Passport Control) is what you should be worrying about. This is the check on whether you are allowed in and for how long. Both Spain and Italy are in the Schengen Area, so no passport checks either.

Thanks for all your replies. I live in Washington and will be in Barcelona for holiday for a week. Then fly from Barcelona to Palermo to meet up wth friends. Am I considered originated from USA or Spain? If Spain, then it seems I have no problem since we do not check in bags . From your reply, it seems that I go through passport control in Palermo, not Rome. I hope this is true .

If I am considered originated from USA, a non-Schegen area, then I worry about going through passport control in Rome with just 2 hour layover time.

Please help me clarify my " place of origin" in this case. I am not sure. Thank you again

Thank you Chris F for clarifying 'customs" and "passport control". I thought they are the same. To me, "security " is for bags, and "customs" is for passport. I guess I have been wrong all along.

As mentioned, since all places are in the Schengen zone and the EU, when you arrive in Barcelona (I assume directly from the US) you will go through Immigration and as you walk out the door, it will be Green indicating nothing to declare, that's customs, no stopping. If you do have something to declare, you need to seek them out near the Red portal. Then spend your week in Spain, go to the airport, and it is just like a domestic flight in the US. Go through Security, they will need your passport, get checked, get on the plane to Rome. In Rome, you will get off in a domestic terminal, and unless you need to change terminals and go through security again, you stay airside and just walk to your next gate. In Palermo, you get off the plane and walk out the exit, no immigration or customs.

You go through immigration and customs when you first arrive in Barcelona. Then you're on your jollies for a week before flying to Rome and Palermo which are internal Schengen flights so no more immigration or customs checks.

Your place of origin has nothing to do with it. When you land in Barcelona from Washington, you will go through immigration, which is where they check your passport and stamp it. Then you are officially admitted. You will then collect your luggage and go through "customs". But unless you are bringing in goods you intend to sell, you just walk out the "Nothing to Declare" door.

Going to Palermo through Rome, they will only check your passport to make sure that it matches your airline ticket or boarding pass, just like here in the USA. Then it is basically a domestic flight. Nobody cares about your nationality, citizenship, or country of origin. You've already been admitted to the Schengen zone, as evidenced by the stamp in your passport that you got in when you landed in Barcelona.

If I am considered originated from USA, a non-Schegen area, then I worry about going through passport control in Rome with just 2 hour layover time.

No, as the others say, when you first arrive USA --> Barcelona that is when you enter the Schengen Area and go through passport control. Barcelona --> Rome --> Palermo is wholly within the Schengen area, no passports for anybody.
Though for any flight, there will be an airline ID check at departure where the airline checks your passport.

And security is a third thing, neither immigration nor customs. Security is checking you have nothing banned on a plane (sharp objects etc.). It happens at the departure airport (the other two are at arrival) and occurs wherever you are flying to, within a country or to the other side of the world. It is nothing to do with crossing borders.

A big thank you to all of you who helped to clarify my concern. You explained very clearly. Have a great day!