Originally Posted by
Goldorak
OK. In fact I replied to the "standby" case of the OP and changing without paying a fee is not feasible unless you are on a flex award, as recalled by KLflyerRalph (I forgot this case - sorry). So my answer was partially right and partially wrong and incomplete. And even when paying the 45 Euros fee, you need to have the fare bucket still available, which is far from being obvious a few hrs before departure. The same applies to restricted paid tickets. Some of them can be changed with a fee, providing the fare bucket is available. Otherwise, you'll need to pay the difference with the new fare bucket, which can be costly.
^
Well, I for one think that you answered the two specific questions asked by the OP perfectly correctly. ^ As you said, stand by and 'free' same day connection are clear no-no's in principle, be it with the award or upgrade ticket and I think that it is what the OP apparently wanted to know.
As mentioned by others - very rightly too of course, if it is an FB ticket booked as a classic award it can be changed for €45 if there is availability in O class (and for flex award in the relevant booking class, I think I?). However, as the OP says there are seats 'in business' rather than O, my guess is that he/she was hoping to be able to use seats that were not earmarked for awards and that would unfortunately be impossible.