Hello there, BoxesNearMe1.

Thanks for sharing your concern here in the Community.  Allow me to provide additional information about applying credit memo to an invoice.

Rustler is correct. There isn't a way to display credit memo(s) on the invoice. You can apply the credit memo to the invoice through Receive Payment. 

Here's how to create the payment and apply it to the invoice:

1. Click Sales in the left navigation bar.
2. Click the Customers tab.
3. Locate and click the customer's name.
4. Locate the invoice you want to apply the credit to and click Receive payment.
5. In the Receive Payment window, enter the necessary information.
6. In the Outstanding Transactions section, make sure that the correct invoice is selected.
7. In the Credits section, make sure the correct credit memo is selected.
8. Click Save and close.

You can read this article for more information: Apply a credit memo, credit or refund to a customer.

Feel free to reach out to us if there’s anything else you need help with QuickBooks. I'll be around.