This module will give the customers the ability to use domains they have already purchased. For example, the client first orders a domain name only and then comes back at a later date and wants to order a hosting service and use the same domain name they already have on their account. With WHMCS, it will not be easy to do that but with this module, WHMCS Existing Domains, you can easily do it.
Need Hosting? Check Out - Hostimony - Web Hosting Providers Ranked by Genuine Customer Reviews