Hi there, 2kpmac,

While you can add a custom field column to your CSV file, please know that QuickBooks won't recognize and display them, as they're not part of the supported mapping.

As a workaround, you'll need to manually add a custom field to your imported invoices after they're in QuickBooks. To do so, here's how:

1. On your QuickBooks account, navigate to the Gear icon and select Custom fields.
2. Click Add custom field if you haven't created one, or select Add field if you have.
3. On the Add custom field window, enter its name and select its appropriate Data type.
4. Select the correct category and tick Invoice in the Select forms section.
5. You can enable the Print on forms option to display this when invoice transactions are printed.
6. Once done, click Save.

Once done, it will automatically be added to your newly imported transactions.

On the other hand, I can see how importing custom fields would simplify your workflow. Although this feature is unavailable, I encourage you to send your feedback to our product engineering team so they may consider this in future updates.

To send one, here's how:

1. Go to the Gear icon, select Feedback.
2. Write your suggestion in the box provided.
3. Once done, click Next.

Please don't hesitate to get back to this post if you have other questions or concerns.