Credit and Debit Notes
Non-Draft invoices are immutable, meaning that after you publish an invoice (when it leaves the Draft status), you cannot directly edit it. Instead, the system automatically generates credit and debit notes whenever billing actions require invoice adjustments. Credit and debit notes maintain consistent and accurate financial records for easier auditing and tax compliance.
Admins and clients can view credit and debit notes by clicking on the note in the Reference column of the invoice’s Ledger section.
Credit Notes
A credit note reduces or eliminates an invoice balance. Businesses use credit notes to document refunds, price adjustments, returns, or corrections after they issue an invoice.
In WHMCS, the system creates credit notes automatically when you perform actions that would have previously reduced an invoice amount.
| Action | Action Type | When a Credit Note Is Created |
|---|---|---|
| Mark Invoice(s) Paid | Manual (Admin) | When you mark an invoice as paid while it still has a remaining balance, the system creates a credit note for that balance. |
| Cancel Invoice(s) | Manual (Admin) | When you cancel an invoice (individually or in bulk), the system creates a credit note for the full invoice amount or for selected line items when cancelling specific items only. |
| Refund Invoice Payment | Manual (Admin) | When you refund a payment on a paid invoice, the system creates a credit note for the refund amount. Refunding an unpaid (partially paid) invoice does not create a credit note. |
| Apply Client Credit to Invoice | Manual (Admin) | When you apply credit from a client’s credit balance to an invoice, the system creates a credit note for that amount. |
| Cancel Invoice Line Items | Manual (Admin) | When you cancel specific line items (for example, a product/service or domain renewal), the system creates a credit note for those items only. |
| Close Client | Manual (Admin) | When you close a client account, the system closes any issued credit notes with remaining balances. If a credit note has a balance, the system creates an offsetting debit note. |
| Invoice Auto-Cancellation | Automated (System) | When the system automatically cancels overdue unpaid invoices (based on your configuration), it creates credit notes for the cancelled invoices. |
| Domain Expiry Status Update | Automated (System) | When a domain expires: If the invoice contains only domain items, the system cancels the invoice and creates a credit note. If the invoice has other items, the system creates a credit note for the domain renewal line item(s) only. |
| Domain Grace/Redemption Fee Processing | Automated (System) | When adding grace or redemption fees, the system may cancel or adjust the renewal invoice and create a credit note for the domain renewal line item. |
| Order Cancellation | Automated (System) | When you cancel an order, the system cancels the associated invoice and creates a credit note. |
| Order Fraud Check Failure | Automated (System) | When an order fails fraud checks, the system cancels the invoice and creates a credit note. |
| Merge Invoices | Manual (Admin) | When merging invoices, the system cancels old invoices and creates credit notes for cancelled invoices. |
| Close a Debit Note with Remaining Balance | Automated (System) | When closing a debit note that has a remaining balance, the system creates an offsetting credit note. |
Debit Notes
A debit note increases an invoice balance. Businesses use debit notes to document additional charges like late fees or underbilling corrections.
In WHMCS, the system creates debit notes automatically when you perform actions that would have previously increased an invoice amount.
| Action | Action Type | When a Debit Note Is Created |
|---|---|---|
| Remove Applied Credit from Invoice | Manual (Admin) | When you remove credit that was previously applied to an invoice, the system creates a debit note for that amount. |
| Invoice Cancellation After Credit Application | Manual (Admin) | If credit was applied to an invoice and you then cancel the invoice, the system creates a debit note for the returned credit before cancelling. |
| Close Client | Manual (Admin) | When you close a client account, the system closes any issued debit notes with remaining balances. If a debit note has a balance, the system creates an offsetting credit note. |
| Add Late Fees | Automated (System) | When the system adds late fees to overdue unpaid invoices (based on your configuration), it creates a debit note with type InvoiceLateFee. |
| Invoice Overpayment Credited to Client | Automated (System) | When a payment exceeds the invoice balance and the system adds the excess to the client’s credit balance, it creates a debit note for that overpayment amount. |
| Close a Credit Note with Remaining Balance | Automated (System) | When closing a credit note that has a remaining balance, the system creates an offsetting debit note. |
Invoice Balance Calculation
The system calculates an invoice’s current balance by combining the original invoice amount, any credit notes it subtracts, any debit notes it adds, and any payments the system receives.
When a client pays an invoice, the system applies the payment to the current balance, including any previous credit and debit note adjustments.
Adapting Your Workflow
If your business’s workflows rely on directly editing non-Draft invoices, you will need to adapt them to take advantage of credit and debit note functionality in WHMCS’s immutable invoices.
For example:
Late Fee Removal After Extension
If you have granted an extension for an overdue invoice, you cannot remove the late fee line item directly. Instead, you must:
- Cancel the existing invoice. The system creates a credit note for the full amount, including the late fee.
- Create a new invoice manually without the late fee.
- Send the new invoice to the customer.
Price Adjustment After Invoice Issuance
You cannot edit the invoice line item to adjust the price. Instead, you must reissue the invoice with the correct pricing.
Adding Forgotten Line Items
You cannot add line items to a published invoice. Instead, you have two options:
- Reissue the invoice, making sure to add all of the desired line items.For steps, see Reissue an Invoice.
- Create a separate invoice for the forgotten item and send both to the customer.
Removing Cancelled Services
If the customer cancels the service after the next invoice generation, the system handles this automatically by creating a credit note for the cancelled service line item.
Last modified: 2026 February 19