Originally Posted by
dc2447
Yes, correct. Apologies, fully flexible of course would not incur the charges.
There can still be big differences in price if you change at the last minute.
The difference in price between a fully flexible D class fare on a short European hop and a fully flexible J class fare is a couple of hundred. If all that is left on the day of the flight is J class and you want to switch, you'll have to pay up.