Hi,
You can purchase several times with the guest checkout. However, if your email address has already been used to create a user account, you need to login instead.
If you already have user accounts when you activate the guest checkout, you have two options:
- you leave the login form on the checkout so that the customers can login instead of guest checkout.
- you delete their Joomla user accounts. That way, you'll be able to guest checkout with their email address again. Of course, the orders of the customers won't be deleted from HikaShop when you do that.