Hi Nicolas,
It's working now, but not sure what did it in the end.
I changed the "show taxed prices" setting to "with tax". However, I'm not sure if that actually did it as before I went back to the page I went and cleared the system cache before refreshing the page. After I refreshed the total price is now adding the taxes.
To test I went back and changed the "show taxed prices" back to no tax, went back to clear the system cache and it's still showing the correct price.
Not quite sure what's gone on, may be just clearing the system cache was all that was needed.
Thanks anyway for your help.
Kind Regards
Duncan