Cancellation fee
 

Affaires ticket US-CDG-Europe r/t. One ticket is AF only one is AF/KL. Suddenly fares dropped $1500-$1800 each. What does AF charge if I cancel and rebook? Just wondering because airfrance.us is saying no modifications although Affaires

AF only is J within Europe, D/Z from/to USA
AF/KL is J within Europe, I elsewhere

I see something about a 300 euro reissue fee but do not see anything else relevant one way or the other

To obtain our opinons, pls help provide Fare Class information (Z, C, D, J..etc), and not just calling it a Business Class ticket. Your e-ticket (Voyage Memo that you get by email after purchasing the ticekt) should also indicate cancellation policy.

Apparently your ticket is a complex one with a mix of different fare buckets.
Even just stating D or Z is not enough because there are many D fares and many Z fares.
if your European fares are in J, it is likely that the biggest restrictions will be on the TATL D/Z fares. Usually, the most restrictive fare (Z in your case) will dictate the cancellation rules. But as said above, there are several Z fares (Z****).

In your case, you seem to want to cancel this ticket and buy a new one (cheaper). Then you should look at the cancellation clause. Is your ticket refundable and what is the fee? If you cannot find it, call AF as their agent can find the rules in your booking.
Note that there are non-refundable business class fares. And because your ticket refund possibility is dictated by the lowest fare bucket, it could well be that you cannot cancel the ticket.

I suppose you cannot just ask to change the booking class on the same flights. It would be considered as a cancellation.

But if you change one flight on both legs, they should reprice the itinerary and it would be considered as a modification.
Or I miss something!

Changing the booking class on a segment would be a change rather than a cancellation. However, when a ticket is non-refundable, the fare rules will normally specify that the non-refundable amount remains non-refundable even if the new itinerary is cheaper (or even, for that matter, if you change the ticket to a notionally flexible booking class). So there is no point in trying to engineer a modification versus a cancellation just for the sake of it.

... Otherwise everybody did this and non-cancellation tickets wouldn't make any sense.