Originally Posted by
In The 216
Log into their reservation, select "Change Flights", put in the new dates/cities, and the system will tell you what you owe for the change.
bad advice - change tool online is horribly inaccurate - it either a) errs our when trying to complete the change, b) doesn’t show options even when available, particularly on partner carriers (which potentially is an option here with AC), or c) overcharges the fare difference (which can be seen when comparing pricing to a brand new flight search). Add in it’s Friday night, when the UA site is wonky anyway due to updates being done. OP should definitely call for options - in fact, best thing is OP to have specific alternatives they can feed to the agent who can verify pricing and complete the change.