I have a co-worker who regularly commutes MCI-YYZ. He books a UA flight number on ual.com that is operated by AC. He never receives credit for his outbound miles, but always receives credit for the return (within 2-3 days.) UA told him it was because there was not an AC rep for him to check-in with at MCI.

From his last 4 trips, his latest non-credit fare basis from MCI-YYZ were WOA7CNX1, VPA21CNX, SPE0NA6, SE7SNQ5.

The return flights that were credited from YYZ-MCI were VPA7CNX1, QPA7CNX1 , SPE06N6, SE7SNQ5.

And yes the last one was the same fare basis for both segments, but no miles on the outbound.

Is this an issue that the fare he is booking is not eligible for miles, or is there some sort of trick on getting UA miles on a UA flight number operated by AC metal?