Originally Posted by
linenbasket
It is a departure tax, so they will if they are connecting.
(
Nope. Not if it's on the same ticket, and the stopover is less than 24 hours. The tax is intended to be for those originating in LON, as has been discussed here quite a bit. If on separate tix, even a transit, though, is supposed to pay the taxes...but not for a same ticket transit.
Cheers.