Troubleshooting Common PDF Invoice Number Issues in WooCommerce

One of the most common support questions for the 'PDF Invoices & Packing Slips for WooCommerce' plugin revolves around invoice numbering. Users often report that numbers are missing, skipping, or incrementing unexpectedly. This guide will walk you through the most frequent causes and their solutions.

1. Invoice Number is Not Displaying at All

If your PDF invoice only shows the word "INVOICE" without a number, the most likely cause is a simple display setting that has been overlooked.

Solution: Navigate to WooCommerce > PDF Invoices > Documents > Invoice. Find the setting for "Display invoice number" and ensure the "Invoice Number" option is selected. This setting controls whether the number is printed on the document itself.

2. Invoice Numbers Are Skipping or Jumping

Reports of invoice numbers jumping by 1, 2, or 3 are often linked to payment gateways. This can happen when a payment gateway triggers multiple order status changes or sends duplicate payment confirmation emails, each of which might try to generate a new invoice number.

Solution: Identify if the issue is specific to a payment method. As seen in user reports, gateways like Cashfree have been known to cause this. The first step is to test if the problem occurs with other payment gateways. If it is isolated to one gateway, you may need to contact the gateway's support to inquire about duplicate notification calls. The 'PDF Invoices & Packing Slips for WooCommerce' team has acknowledged this can be an issue with external payment processing.

3. Incorrect Number Sent to PayPal

Sometimes, the WooCommerce order number is sent to PayPal instead of the custom PDF invoice number. This is typically not a function of the PDF invoice plugin itself.

Solution: This behavior is controlled by the plugin you use to connect WooCommerce to PayPal. You will need to check the settings of your specific PayPal gateway plugin to see if it can be configured to use the custom invoice number generated by the PDF plugin.

By methodically checking these common areas, you can usually resolve invoice numbering problems without needing to write any code. If your issue persists after these checks, it is helpful to gather specific details, such as which payment methods are involved, to seek further assistance.