If you are receiving too many queries from potential clients then you need this add-on to work with WHMCS. Auto Create Clients will help you set them up with one click.
Auto Create Clients has the ability to:
Create Clients from Tickets
Automatic Run Cron to Create new Clients by looking up in tickets - It can also be initiate manually from Module Settings (if Cron is disable). It will also assign tickets to your existing clients that they have opened before registering an account
Cron can be enable/disable from module configuration page