Originally Posted by jsloan

Technically, UA can bill you for the fare difference. They won’t, if it’s not a one-off, You can get a prorated refund if there are IRROPS on the second leg, of course, and there was one poster a couple of years ago who claimed that UA routinely gave him refunds in this case, even without any delay, but I can’t imagine why UA would do that and never really believed the guy.