Manage Legacy Invoice Numbers
This guide explains the legacy method of customizing invoice numbers in GST Pro.
Legacy customization steps
Open General Settings
Go to GST Pro → Settings → General Settings.
Select custom invoice format
Scroll down to Standards and Formats.
Under Invoice Number Format, select Custom Invoice Numbers.
Set initial invoice number
Enter your first invoice number to define the starting point for your sequence — for example, the first order in April.
You can enter a **negative number** if you want the count to start below zero.
Add prefix and suffix
(Optional) Add a Prefix and/or Suffix to your invoice number format for identification.