Originally Posted by
ajcopley
Flying YVR --> SEA --> AMS (purposely picked this routing for biz class pricing). Wondering if I have to go through U.S. customs and immigration in YVR since I'm flying to SEA (even though connecting to AMS)? I think the answer is yes, but wasn't sure...
Yes, you must go through US immigration/customs pre-clearance at YVR in order to get to pre-clearance area for Canada-US flights (unless you have a late night flight out of YVR and pre-clearance is closed, in which case you'll have to do it at SEA). There's no short-cuts for transit passengers.