Hi Anita
Many thanks. I've only just come back here and seen your message, so my apologies for the late reply.
In fact the upgrade that I purchased turned out to be just the Windows version (there's no option to specify Mac during purchase), so I called the UK Store (in Germany) where after much consultation the solution was to cancel the order and re-order the shipped version. After 12 days this has still not arrived (Order Status shows as "Partially Shipped"!) but I do have the License number. Hopefully all is now OK. I wish they'd told me what you told me! (And actually the website should handle this better).
Thanks and regards
John