A long missing feature from WHMCS is the ability to send proper account statements to customers showing all their unpaid invoices.
This module will allow the following functionality.
NOTE: It does not work with PHP 7, I am in the process if getting that fixed.
The best place to start if you need help with a specific product is to contact the developer. All WHMCS Marketplace developers have both a website and support URL listed.
1.2 fixed to work with whmcs 6.x
CleanHTML Invoice and Quote Free template.
As WHMCS does provide tax rules options where you can configure your GST tax but we have some extra features in our module that makes it stand out and necessary to use.
The definitive solution for all your billing needs plus a lot of additional features
Automatically pay commissions to your salespeople, resellers etc.
Introduce extra billing models and charge your clients for actual server resource usage.