I was following Acorns #14 to update from premium 365 to v15. (Thanks Acorn!)
I have 365 on two computers and wanted to keep them plus v15 on both. When I came to register first time, I was instructed to de-activate to be able to complete, which I did. It also said that this can't be done again for another 30 days. I put in a ticket to Xara support explaining what I wanted. The reply was:

Thank you for your message.

Version (15) and version (12) share the same two activation slots, therefore it's not possible to activate two instances of version 12 along with two instances of version 15.

If you would like us to reset your activation limit, please let us know in response to this email.

Best regards,
Thomas

I now have v15 on both machines but not any 365 (12) which I wanted.

P.S. Xara support replied next day under 'Normal' priority.

Mick