Account invoice refund line

When you use the standard refund/credit note wizard on an invoice, this module adds an extra option called "refund lines". Tick it and a new "Invoice Lines" tab appears where you can choose exactly which invoice lines should be included in the credit note.

The list shows the lines of the invoice you started from (product, description, quantity, discount, taxes, unit price and subtotal) and they are read-only, so you only select them; you cannot edit their values there. Only lines belonging to that invoice can be picked.

If the option is left unticked, the wizard behaves exactly as before and the whole invoice is reversed. If it is ticked, only the selected lines are copied into the new credit note, with their original accounting and tax information, and the rest of the invoice is left untouched.

This works on the reversal wizard used for both customer invoices and vendor bills, so it applies to sales and purchase corrections alike. No new menu is added; the change appears inside the existing credit note wizard.