Originally Posted by FlyerGoldII

I spoke to the US CBP officer at the NEXUS office at YOW - he was not quite sure about the answer to the question - as he stated that the trusted traveler number (listed on my nexus card or on your GE card) is linked to the passport - so he stated that one could enter either one when checking in, for a successful processing through GE.

Obviously, my experience with on line check in with the trusted traveler number followed by passport entry at the GE machine, did not go smoothly - which you have implied with your statement above.

But your answer does pose a interesting problem - let us say that one goes on a return ticket (ie one pnr) on a US airline between USA and Canada - and one wants to access both PreCheck when departing from USA, and GE when departing Canada when going through US preclearance at a Canadian airport. What does one do about check-in - or can one enter both the passport number and the trusted traveler number?

Canadians with the nexus card (with GE privileges) can check in with the airline in Canada (when flying to a US destination) with nexus' trusted traveler number (especially at airports with US preclearance), rather than the passport. If so, can the trusted traveler program number be transmitted from the airline's check-in to the GE machine, when entering the passport at the GE machine? Yesterday's US agent at YOW said yes, but the US agent when I actually tried this a few weeks ago said no.