Billing Logic

Specific billing logic governs the automation for many of your business's most important tasks, including ordering, payments, and provisioning.

Troubleshooting Invoices

Issues with invoices and invoice generation can be due to many causes, some of which may not be obvious at first.

Credit and Debit Notes

Use credit and debit notes to modify immutable (non-Draft) invoices. Credit and debit notes maintain consistent and accurate financial records for easier auditing and tax compliance.

Invoice Management

After invoice generation, you can easily manage your clients' invoices, including payment, splitting invoices, cancelling them, and more.

Invoice Configuration

The system uses your Automation Settings configuration to determine when to generate invoices for your customers and how to format them.

Custom PDF Invoices

Invoice and quote PDF files use a customizable template file system in the templates directory of the active WHMCS system theme. If you use a self-hosted WHMCS installation, you can use this templated system to customize your PDF invoices and quotes.

Invoices Tab

The Invoices tab in the Client Profile allows you to view and manage all of the client's invoices.


Change Invoice Instructions

Update the payment gateway configuration to change the invoice payment instructions for Mail in Payment or Bank Transfer invoices.

Change Your Payment Address

Change the Pay To Text address on generated invoices. Newly-generated invoices will use the new address after you save this change.

Configure Invoice Immutability

Configure Invoice Immutability to choose whether you can edit invoices after they leave the Draft status and whether the system generates credit and debit notes.

Configure Invoicing

Use Automation Settings to define how and when WHMCS invoices your customers.

Configure Payment Reminders

Configure WHMCS to send payment reminders before customers' payment dates and to send additional notices after a bill is overdue.

Convert Invoice Currencies

Convert invoices from one enabled currency to another before the client makes payment using the Convert To For Processing option.

Create a Mass Payment Invoice

Mass Payment allows customers to quickly and easily pay for multiple invoices in a single transaction, reducing your processing costs.

Create a Renewal Invoice Early

Manually generate an invoice for a client's service, product or domain addon, or domain renewals before the system generates the next automated invoice.

Create Separate Renewal Invoices

Automatically generate separate invoices for services that have the same due date, either for individual clients or client groups.

Customize Your Invoice Numbering

Customize the invoice number that the system generates for each invoice by configuring the Custom Invoice Numbering Format setting.