Originally Posted by
jphripjah
Is this in their published rules somewhere? I've never noticed any warning of that when they tell you before booking what the downsides are of booking basic economy.
No; it's based upon anecdotal reports:
UA Bag Interlining If Separate Tix with *A Partners (YES) & Non *A Partners (NO)
You could probably make an argument that their policy cals for the bag to be checked through even on a BE ticket, given that they don't call it out as an exception, but if they refuse, I'm not sure what Plan B would be.