upgrade ticket
 

Just tried to upgrade one of the segments of my ticket to business class only to be told it's not available for sale yet. Funny thing is it show's when booking online that business class is available. When trying to change my ticket online I get an error message to call reservations. Is this a bug or does US air sometimes remove business class from some flights. Flight is YYZ-CLT October 2nd. Morning flight is wide open in business.

Just because a business class seat is available for sale doesn't mean upgrade space is available. Pretty sure this rule applies to every airline in the world, they're not going to give away the entire cabin to upgraders before a single person pays for it.

I was attempting to change my ticket to business but they said it's not available for sale. I'll phone again and indicate that i want to change my outbound journey to business class and see what happens. Attempting to do it online results in an error message to call reservations.

Just FYI, its an Embraer E175 which means your first class experience is going to be pretty minimal over coach.

First on board: yes
Better seat: yes

After that, the differences are marginal. There will be no hot breakfast - just a snack basket. A PDB (probably) and drink service en route.

I know. Just trying to buy business to make bronze with my BA FF program. I need 50 points and the business class flight is 40 points with BA and only 5 in coach as my ticket is currently a deeply discounted ticket. I'll keep phoning US and see what they say.

Can you post the entire itinerary? MSL may not allow for tickets in that class to be sold, even though it's showing available for that single segment.

There may also be some confusion with the term "upgrade". Since it sounds like you're willing to pay, I think you should ask to change the fare class.

MSL aside, there is plenty of room in business on 4464:

The itinerary is 4699-4805 on the 2nd of october then 4805-4665 on the 5th of October. Both 4699 and 4665 have availability for J just thought they might be swapping another plane and didn't want to sell me the revised ticket. I'm on a Q fare outbound and N fare return. I was given a fee a week ago to revise the itinerary online but since then it gives me an error message and said to call reservations. Wondering if this has anything to do with the US AA merger.

Can you post the cities? I can't find a way to look up flights by flight number that far in the future.

Toronto-Charlotte-Tri Cities/ Johnson City outbound October 2nd return October 5th. I'm looking at upgrading the Toronto-Charlotte leg of the journey to earn extra points for my FF status.
YYZ-CLT-TRI Outbound October 2nd return October 5th.