Thanks for dropping by the Community and sharing details of your concern. I'll impart insight to help you handle the negative paid invoices in QuickBooks Online.

It could be that the negative amount is from the overpayment or credits. You'll want to check if these are duplicates or not. Then, verify if there should be an invoice to apply it to. Create one if needed.

Here's how to apply the credit to an invoice you already created:

1. Click + New in the left panel and choose Receive payment.
2. Choose the customer, then the credit and the invoice.
3. Click Save and New or Save and Close.

You can follow these steps to apply the credit to a new invoice:

1. Click + New on the left panel and choose Invoice.
2. Create the invoice.
3. Tap + New and select Receive payment.
4. Choose the credit and then Save and Close.

I'll add this article you can use in the future: Clear up customers with zero net balances in the Accounts Receivable Ageing report.

Feel free to post here again if you have further QuickBooks-related concerns. We are available 24/7 to lend a hand with each of your queries. Stay safe!