WHMCS stands for Web Host Manager Complete Solution
WHMCS is the all-in-one client management system for Reseller Hosting. It is a WHM plugin that gives you billing and support capabilities so you have all the tools to run their hosting business. With the successful integrated facility of WHMCS billing, hosting packages, payment gateways, server provisioning APIs, domain registration and fraud protection services have become too easy to handle.
WHMCS has proved to be an incredible solution as it has been an one-stop hosting solution for things such as handling Billing and Support ticket requests, It is compatible with the major payment gateways such as PayPal, Google Checkout, and Authorize.Net, and includes many features such as the ability to use various currencies, create invoices, and create promotions.