Cancellations:
Once you have booked a space, you can cancel it up until 24hrs before the class (8.15pm the previous day) & receive a full refund (minus 20p per space paypal refund fee)
Class Transfers:
I've just managed to add the option of class transfers - so now, up until 10am on the morning of a class, you can transfer your space to a different date, if you find you are poorly, or another unexpected situation arises.
Both advanced cancellations & class transfers need to be done by the person who made the booking, via the link on their original confirmation email :)