Free Community Addon: CW Invoice Mutability for WHMCS 9.x

[ricrey]

Hi everyone,

I would like to share a free community addon I created for WHMCS 9.x:

CW Invoice Mutability for WHMCS 9.x

Repository:
https://github.com/RicRey1988/cw-invoice-mutability-whmcs-9.x

WHMCS 9 introduced invoice immutability for non-Draft invoices. I understand the reason behind this change from an accounting and audit-trail perspective, but I also noticed that some administrators still need a controlled way to manage invoice editing in specific internal cases, especially before an invoice is paid or before it is synchronized with an external tax/e-invoicing system.

This addon provides an admin interface to manage the current WHMCS invoice mutability compatibility option without manually editing configuration.php.

Main features:

• Enable or disable invoice mutability from the WHMCS Admin Area.

• Automatically add or remove the current WHMCS compatibility flag:

  $allow_adminarea_invoice_mutation = true;

• Create a backup of configuration.php before modifying it.
• Optionally hide the WHMCS Admin Area warning banner about invoice immutability being disabled.
• Advanced/emergency mode to convert eligible Unpaid invoices back to Draft.
• Audit log table with invoice snapshot, invoice items, transactions, admin ID, IP address, reason, and timestamp.
• Safety checks to block Draft conversion when the invoice has transactions, payment date, or possible external/tax authorization references.
• PayPal donation link included for anyone who wants to support the project.

The advanced Draft mode is intentionally restricted. It is not intended for already-paid, fiscalized, externally authorized, or tax-reported invoices. In those cases, the correct workflow should normally be credit notes, cancellation, voiding, or re-issuance according to local accounting rules.

Installation:

The folder must be named exactly:

cw_invoice_mutability

Final WHMCS path:

/modules/addons/cw_invoice_mutability/

Required structure:

modules/
└── addons/
    └── cw_invoice_mutability/
        ├── cw_invoice_mutability.php
        ├── hooks.php
        ├── README.md
        └── lib/
            └── CwInvoiceMutabilityTools.php

You can clone it directly with:

cd /path/to/whmcs/modules/addons
git clone https://github.com/RicRey1988/cw-invoice-mutability-whmcs-9.x.git cw_invoice_mutability

Then activate it from:

Configuration > System Settings > Addon Modules

After activation, go to:

Addons > CW Invoice Mutability

This addon is free and community-oriented. It is not affiliated with WHMCS.

If it helps you, donations are welcome:

https://paypal.me/hostingsupremo

Feedback, improvements, and pull requests are welcome.