WHMCS 9.0 Credit and Debit Notes: How It Works & Setup 2026

WHMCS 9.0 Credit and Debit Notes: How It Works & Setup 2026

WHMCS 9.0 introduces full support for credit notes and debit notes, simplifying global invoicing and refund workflows while helping you stay compliant with VAT, GST, and financial reporting standards. This guide explains how they work and how to use them in WHMCS 9.0.

What Are Credit and Debit Notes?

A credit note is a document that reduces the amount owed (e.g. refunds, discounts, or corrections). A debit note increases the amount owed or records a charge. Many jurisdictions require these to be issued in a specific format and linked to the original invoice for tax and audit purposes.

Before WHMCS 9.0, handling these often meant manual documents or workarounds. Now you can create, format, and track credit and debit notes natively in WHMCS.

Immutable Invoices and the Ledger

Starting with WHMCS 9.0, non-Draft invoices are immutable. You cannot:

• Edit transactions on an invoice
• Add or remove items from an invoice

This keeps invoice history consistent for tax and audits. Corrections and adjustments are done via credit notes and debit notes, not by editing the original invoice.

The Transactions section of an invoice is now called the Ledger. In the Ledger you see all transactions for that invoice, including credit and debit notes.

New Role Permissions

WHMCS 9.0 adds role permissions for credit and debit notes:

• List Credit and Debit Notes — Allow admins to list individual credit and debit notes
• Create Credit or Debit Note — Allow admins to create credit or debit notes for a client
• View Credit or Debit Note — Allow admins to view details of a credit or debit note
• Manage Credit or Debit Note — Allow admins to publish a note and edit it while in Draft status
• Delete Credit or Debit Note — Allow admins to delete a credit or debit note from the system

You can assign these in Configuration > System Settings > Administrators (or your role management area) so only authorized staff can create or manage notes.

Benefits for Your Business

Related WHMCS 9.0 Features

• E-Invoicing Peppol BIS 3.0 — automated compliant e-invoices for key markets
• WHMCS 9.0 Release Guide — full feature list and upgrade steps