What do I do if a payment was made and the bank account attached to our quickbooks account no longer exists?

Hi there, ashton-farnswort. I can share some information on how you can handle this payment in QuickBooks Online (QBO). 

If you're referring to online banking, you can manually receive payments and place them into the Undeposited Funds account. This way, we can deposit them at your real-life bank into a single transaction.

To do that:

1. Go to + New and select Receive payment.
2. Choose a name in the Customer dropdown.
3. Check the box for the invoice you're receiving payments for.
4. Select Undeposited Funds from the Deposit to dropdown.
5. Fill out other necessary information.
6. Select Save and close.

However, if you're using QuickBooks Payments, we'll have to contact our Payment Support Team to review the security of your account. They can help and provide you with the best way to handle this kind of situation. You can contact them through this link: Payments Support.

For your future guide, you can check out this article if you'll have to return your customer's money as a refund: Record a customer refund in QuickBooks Online. It contains various scenarios to track customer refunds properly.

Feel free to leave a reply if you require further assistance with receiving payment in QBO. The Community team is here to help you anytime. Have a good one!