Originally Posted by
yxxmike
It's showing as a AC flight number, but because it's UA they wont show the booking code. The rest of the segments are booked under a "K" booking class.
Just to confirm, are you booked on flights as "AC XXX" or "UA YYY operated by AC XXX"?
If you are booked on AC XXX then you are likely OK as AC doesn't typically sell Tango fares on transborder. If you are booked on UA YYY (operated by AC XXX) then there could be a problem earning status miles, but even then it is not likely.