From v2+ we implemented a version control system to all of our WHMCS Templates. This ensures that it's quick and easy to find the version of the template you're running and also the version of WHMCS it supports.
You can find your template version in the following file:
At the top of this file you'll find the current version you're running. This file also includes a changelog showing the new features/changes made to each version. This file will be automatically updated when a template update is installed.
WHMCS Version Support
You can find the version of WHMCS your template supports in the following file:
This file will update automatically every time a update patch is installed.