Changing attached subscription

I've bought HikaShop Business version. However I'm being asked to attach a URL to the subscription. No problems with this except that the URL I'm putting it on is a temporary one, and once the site's fully developed and approved by the client, I'll be moving it to another hosting space, with a different primary domain name.
Secondly, I have particular requirements for the ecommerce system used on this site, due to the nature of the product (chromatography validation), and if the client is not completely happy with the functionality, I will (with regret) have to use another system instead. If this happens (which hopefully it won't), I already have another site running HikaShop starter, which will need upgrading to the Business version in the near future. So instead of buying a second package (which I'm happy to do), I would instead make use of the package I've just bought. Again this will mean changing the domain name attached to the subscription.

My question, obviously, is: can I change the domain name attached to the subscription? Or is it the case that once I've entered the domain name I'm installing it on initially, I can't switch it to another domain?

Thanks, Curtis