First off, this thread should probably be moved over to the Nexus Info. thread in the trusted travelers forum, as that seems to be the most appropriate place.
To the OP: The variety of answers you have seen in other threads is not going to change here. There are some who believe they can travel without their passport using Nexus by air, and others (like me) who believe you need it. If you go back through the NEXUS info thread, this has come up multiple times, sometimes by a poster who is asking simply to convince themselves they don't need it, and arguing with anyone who gives them advice that they should carry it.
Many have been told they need it at their interviews. Some have been asked to show a passport at secondary (me included, and I'm of the opinion that if (when) I get a random secondary and if I can't produce it, I don't want to know the officer reaction, nor what will happen to my Nexus). Not to mention some carriers may have different requirements for ID and a Nexus may not be accepted by an airline (even at YYZ, UA staff always insist on a passport and not a Nexus). Just a few reasons I wouldn't travel by air without it.
In regards to some of the other comments:
Originally Posted by
yvr76
I've even been asked for my passport when crossing at a land crossing. Specifically the officer wanted to see my TN work permit. If you have any kind of visa or work permit, then you should carry your passport with even if you're travelling by land or sea.
You always must have your visa/work permit available, Nexus or not, if that's your authorization for entering the country. I hope there aren't those out there who think they can enter, say, the US to work without a copy of their work permit if they are not a US citizen/PR.
Originally Posted by
flyquiet
Ditto what canadiancow said. Technically, the card is enough to operate the equipment IF you are not "randomly" selected for spot check, in which case they rebuke and possibly penalize you for not having the required document in your pocket or bag.
I would note that I have been required to show passport to AC before being allowed to board, despite using my NEXUS as APIS and check-in ID. If you can't get on the plane, what will happen at the customs and immigration hall is moot.
This.
Originally Posted by
flyquiet
It does not say on the screen that you can do it. You have to be observant and notice that the markings on the card resemble the markings on the passport. Just insert so those are in the same orientation.
My dual-citizen daughter was told she could use her US passport on GE machine. Do you have both US and Canadian, or do you have Canadian and some other passport?
To your first point, yes, evidence seems to suggest that it does work in the case of GE machines, though I think the coding is a bit different on the Nexus card and doesn't necessarily work everywhere. I haven't tried it for a long time, but I used to at ex-US check in kiosk's, which I could never get to read a Nexus card even though they will a passport.
As for the second point, I am a dual US-Canada citizen, and was specifically told that only my US passport would work in the GE machine. I've never tried my Canadian, but what was said makes sense, as US citizens are not supposed to enter the US with a different passport, even if dual.