Originally Posted by
emcampbe
I've always had ETCs work online if the terms are met.
Is there a partner segment involved in both of these itineraries? If so, you can't use an ETC - they only work on UA/UAX only itineraries, and so the message you received is normal. This is what I find most often the "issue" when people say they can't use an ETC.
Same experience here, a snap to use online, except for that time I wanted to use it to fly on LH.
With OP's Doha itinerary I can see that as a likely issue. OGG?