WHMCS is your all in one client management system to handle client management, billing & support interface for web hosting businesses.
Before purchasing a hosting package, people can check to see if a host has a valid whmcs license before buying form the host.
WHMCS provides License Verification Tool, that allows you to check if a website is authorized to be running this software.
Go to the following WHMCS URL
Next, put your url that you wish to check then click on “Submit” button.
If the website is verified, we will get result as below.
This domain is authorized to be using WHMCS.