We arrive in Chicago from Toronto on Air Canada and have a 45 minute layover before leaving on a domestic flight. Is that possible? Won't we have to go through customs?

Won't we have to go through customs?

Yes, and grab the rail to your next terminal, and pass through security, and find your gate, and board before they close the doors

You will go through US Customs in Toronto. You will arrive in Chicago at a domestic terminal, so unless you have to change terminals you should be fine. If you do have to change terminals, hit the ground running because you will need to clear security at the second terminal.

From the Toronto airport website:

"For the majority of U.S. flights, guests leaving Toronto will go through U.S. Customs in Toronto, which allows you to arrive in the United States as a domestic passenger."

However, I'm never sure with north Americans whether "customs" means "customs" as in baggage, or "customs" as in what everyone else calls immigration and passport control, or both.

Your other post has you flying Boise-San Francisco-Toronto apparently as part of a Boise-Athens routing. Are you just changing planes in Toronto?

So I arrive in Toronto from Athens, and I go through customs there, and then land as a domestic passenger?

yes

Yes, my flights got completely changed on us. We fly Boise, San Francisco (yes, the wrong direction), Toronto, Athens. Then Athens, Toronto, Chicago, and Boise.

Toronto is just to change planes.

It looks like Air Canada lands in Chicago at terminal 2 and United Express leaves from terminal 1. Do you know if we need to go through security between those?

If your flights got changed you don't have to accept the new routing. Make them come up with something better.

This may help for Toronto: http://torontopearson.com/Connecting.aspx#

Thanks. Unfortunately, that was the best. Boise isn't the easiest place to arrange flights from.

If you manage to get your flights changed, you can connect airside between T2 and T1 at O'Hare. It's about a 10-15 minute walk depending exactly which gates are involved. United also operates a shuttle between gates E3 and C9, but the attendant sometimes advises that it may be faster to walk than wait if the line is long. Here's a map: http://www.united.com/web/en-US/cont.../maps/ord.aspx

Is there still security to go through at another point? I was really surprised when I flew through Newark (yeesh) and had to go through security twice between flights.

I hope that isn't the case at O'Hare...haven't been through there in ages!

All the domestic terminals are connected behind security. So, if you land at one, you can walk (or shuttle) to the others without exiting the secure area.

You usually always have to go through Security a second time IF you have had any access whatsoever to your checked bags when you change.

T1 and T2 are both airside. There is no security between them a number of United Express flights depart from T2. I don't know if Boise would be among them.