Originally Posted by
dyzs
The fare class is what decides if you earn 100%. Unfortunately, not all of UA's fares translate into the same fare class with AC. The simplest solution is to follow the
earning chart. Usually this ends up requiring buying one or two fare classes higher than AC starts flex at so W at minimum.
If buying from UA, W minimum for 100% but the link in post #2 shows that W is 50% earning if the UA flight is booked by AC. The bottom of my stomach dropped out when I first checked the link because I just went through a whole rigamarole getting UA to stop messing with my booking and down-grading my booking below W.