Is it possible to process negative invoices? I would like to put customer returns and new purchases on one invoice even if we owe them at the end.

Hi there, Nickie4. Thank you for reaching out here in the Community. The option to process a negative invoice in QuickBooks Online is not possible.

Since an invoice reflects income or money owed to your business, processing a negative invoice balance is not possible. I suggest processing a Credit note for the return first, then applying the credit note to the invoice for the new purchase.

Here's how:

1. Hover the +New icon, then select Credit note.
2. Select the customer, then select the items they've returned and enter the amount.
3. After creating the credit note, create an invoice for the newly purchased items.
4. When processing the payment, tick the new invoice, then scroll down and apply the credit note you've created.

You may refer to this article for guidance in applying a credit memo.

If you have other concerns related to QuickBooks, don't hesitate to reply. We're here to help.