Forgive me, I'm not sure that this topic belongs here, but I don't know where else. I will be traveling from ORD-ZRH-CPH-DEL. 1st leg is AA, 2nd is SR, 3rd is SK. Obviusly I will have to do customs in DEL, but will I also have to in ZRH, or CPH. I have only been to Europe once, but it seemed like flights within EU were treated like domestic flights in US. IF ZRH-CPH flight was in an unrestricted area, then wouldn't I have to go through immigration at ZRH in order to just prevent anyone from walking out of the airport. I talked to SR and they thought that I may have to do customs in CPH, but they didn't sound very sure. Since I am a US citizen it shouldn't be a problem anyway, but I was just curious. If it makes any difference, i am on 2 separate tickets, 1 to cph, the second from cph-del.

no costums to clear in Zurich, Switzerland. Just make sure that at the original check-in (ORD) your luggage is right away checked through to your final destination too (DEL).

(Switzerland is not a EC member, but that doens't matter, you stay in transit in Zurich, with a lot of shopping possibilities).

If you are going to be staying long in CPH then you do customs there. If you have checked baggage, do not check it all the way to DEL.

what reasons (besides the possibility to have accaess to the checked luggage) is there to not check the luggage through to DEL (from start)?

As long as you arrive from and continue on to points outside of Denmark you should not need to clear Danish customs (unless you check your baggage only to CPH in which case you will need to pick it up and take it through customs to check-in).

If you arrive from inside the Schengen area (the EU countries minus the UK and Ireland plus Iceland and Norway, IIRC) and continue on to a destination "outside Schengen" or vice versa you go through immigration (passport check), but no customs with the possible exception of destinations within Denmark.

If the person is staying for a day or so in CPH, the checked luggage if it gets snafu'ed then DEL is not exactly a great place for lost / delayed luggage.

if CPH is a stopover (stopover definition is > 24 hours or next connecting flight, whatever is longer) then luggage can't be check trough anyway.

but anyway: SK has only one flight/day to Delhi (I have taken this one, but reverse DEL-CPH, 3 times in the last 3 years).

I have 6 hrs at cph. Will arrive at 4:20 pm and leave at 10:40pm. I am planning on checking my luggage all the way through as long as they let me. I talked to AA and they said that it shouldn't be a problem.

checking your lugggage through ZRH and CPH will, for sure, not be any problem.

Enjoy your trip without luggage hassle - until you wait for it in DEL (at least an hour or so ...).