OP - You are not seeking to change fare class, but fare basis. That will generally incur whatever change fee your ticket specifies, e.g. $200 + fare difference for LAX-CLT.

Technically he is correct. A fare class is the letter designator. Changing from first to coach is a class of service change. Granted it is all just semantics.

OP, I suggest checking what the fare difference is to just upgrade to A/P. If the fare difference to W/V is let's say $100(+$200 change fee) and the fare difference to A/P is $350 (+$0 change fee), I'd just change to A/P. This will also get you 2.0EQP instead of the 1.0EQP of W/V.

Don't forget COS bonus...

I was told today by a rep from CS that when changing from Y to F, the change fee would only be waived if the itinerary didn't change. This was in response to my query about why I was charged a change fee (plus fare diff) when I recently made such a class change (I'm told to expect a refund).

I'm thinking to upfare from Q to I (LAX-HND). It's already ticketed.
If I understand correctly, change fee won't occur with exact the same flight/date.
What if I want to change it to LAX-NRT on the same day departure?
Is it considered as the same itinerary and no change fee?

Hopefully I want to change my departure date without change fee as well, but probably I need to pay change fee if I change the date, right?

You need to pay either the economy change fee plus fare difference or fare difference plus the business class fare difference

What is the change fee on the business class ticket?

$200, I think.

I didn't change the date but I was able to change it to LAX-NRT from LAX-HND when upfaring without change fee. The agent told me that the I fare is to "Tokyo" which means the price is for both, so I just paid the fare difference (I fare - Q fare) and not required to pay the change fee to upfare.
If I want to change the date, I need to pay $200 change fee after upfarinng is done.

Change single segment from Y to F
 

I'm making a one day return in November. Now booked in Y but would like to have it in F (EQM reason).Is it possible to change just one segment (or the outbound only with 2 segments) only and pay the fare difference?

Will the change fee apply or only the fare difference?

Yes. Call AA and tell them you want to "upfare" the single segment.

In this scenario, you cannot change the flight, just the cabin. When you do that, NO change fee applies as you are not changing the flight. What you will have though is a fare difference calculated to get into F.

If they try to charge a change fee, HUCA or ask for a supervisor. Not all agents know how to do this but it is an acceptable practice.

Try searching forum for "upfare" to get better details.

Thanks a lot for the info!

It'll be difficult if not impossible to upgrade/upfare just one segment of a multi-segment trip, becuase they'd have to break the fare and it would likely drive the price higher (and I could see them not doing this extra work without a change fee). For example, if you're flying LGA-ORD-DSM, then your fare is for LGA-DSM. That you connect in ORD is mostly inconsequential. Thus, upgrading just LGA-ORD would probably require them to construct a fare based on the fares for LGA-ORD (in FC) + ORD-DSM (in Coach).

But changing just the (entire) outbound or return is not a problem at all.

I have an open jaw JFK-LAX/SEA-JFK ticketed in Y. If I wanted to upfare only JFK-LAX, would the fare difference be half of the discounted rt biz fare or the more expensive one-way fare?