I currently have a full retail version of CS5 for windows but will soon be changing to Mac, can I purchase the upgrade version of CS6 for the Mac without buying the full retail version again?
Yes. Read: Order an Adobe product platform swap or language swap. It essentially means you buy a normal upgrade, but need to handle it through Adobe directly to exchange serial numbers.
Thanks for your prompt response at least I now know it is possible and I will pursue this.
Retrieving data ...