Ok, thanks for that, amarylis, and d'oh!
Actually, it's not really that big a deal as we have no plans to move, but if we ever did decide to go back in future it's good to know about it.
I see you're moving to Manchester this year, I really like it up there. I'm driving up there tomorrow (from Gatwick, ugh!) for the weekend to meet up with DW and brother-in-law and fiance. We originally looked to move there but there were any suitable jobs for my field at the time so we're down South in Buckinghamshire.
Thanks Robatwork, good to know the DCF was so easy!