How to modify the Invoice Promotion Code field?

Overview

You have a text box in the Invoices that you're not using and want to modify, such as the "Promotion Code".

Solution

Sadly it would not be possible as the core fields are used by the application for various calculations. In the example above, the field Promotion Code is part of the core field and used in the calculation within the sales document, as described in the article regarding Managing items: Promotions.

As a workaround, it is possible to use a custom field from the invoice, and then add that custom field to the form.

This can be achieved by following the steps below:

1. Open any Sales Invoice from Invoicing > Sales Invoices, and open the Custom Fields tab:
   
2. Right-click on the desired column, and choose Properties.
3. Assign a name to this column using Field Name.
4. Click on the [...] button for Possible Values:
   
5. Use this dialog window to control the choices:
   
   Replace will update the selected choice, Add adds a new choice, and Delete will remove the selected choice. 
6. Click OK to update the choices.
7. Click Save to update the properties of the line item column.
8. Open the SALES INVOICE Document - system Form through Form Designer, by navigating to File > Setup > Forms: 
   
9. Add the custom field to the form. For details about how to do that, please refer to the Forms Designer document.

In case that you need this new field shown in any report, you may need to customize the report. In this case, please reach out to your Customer Success Manager for the option for customization path.