Miles used to upgrade at airport&FC statement

Hi

Just wondering, when I use FC miles to upgrade at the airport on the day of a flight, when these should usually show up (as in the 'withdrawal') on my FC statement?

Thanks
Andy

[preiffer]

It can be anywhere between 0 hours and a month or so, depending on how quickly the airport get the slip of paper sent off...

[Decker]

or sometimes it never happens...