You can add custom fields in the header section, footer section, additional charges section and on the line item section of the invoice. But in this tutorial we will see how to add custom fields for additional charges.
Custom fields for additional charges and discounts of the invoice:
To add custom field for additional charges of the invoice. simply add a column with name additionalCharges.field_Name in csv.
For example, if you want to add a custom additional charges field on the invoice which says Shipping Charges, Transportation Charges, Packaging Charges, simply add a column in the csv with name
"additionalCharges.Shipping Charges", "additionalCharges. Transportation Charges", "additionalCharges. Packaging Charges".
You can see the example below: