Argh, I need to vent at the system and myself as clearly I've missed the highly important bit of info!
I was with one employer before being transferred by TUPE to another employer. First employer operated a childcare voucher scheme that I paid into and have about £550 in there (I really want to cry).
What I didn't realise is that once you leave an employer the only way you can use that money is for childcare except I probably won't need to now do it's stuck there as I can't get a refund as not a current employee.
(Off to cry angry, frustrated tears which may be PMT induced as much as anything)