Customize Your Invoice Numbering

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








Duplicate Transactions

Troubleshoot and resolve issues with multiple duplicate transactions occurring for the same service or invoice.


Enable Proforma Invoicing

Enable proforma invoicing, which ensures sequential invoice numbers for paid invoices. Some countries' accounting practices require this.


Invoices

The Invoices tab in General Settings allows you to configure how WHMCS generates and sends invoices and applies late fees.