Thanks for posting this, Suzie, because I'm also in the UK and was looking to purchase FitDay PC.
I'm surprised that there is no option for UK users to buy FitDay
I've bought American software before from several companies and never had a problem. If I pay by credit card, my bank does the necessary conversion for me - paying the company in dollars and converting it to UK pounds for withdrawal from my account.
OK, so the support may be by email but that's fine.
I can't help feeling that FitDay is missing valuable business by excluding customers outside the US though