Customer paid wrong account

You can receive the payment, AngelBK.

You will have an option to select the open invoice from the outstanding transactions section. Here's how:

1. Click + New on the left pane.
2. Select Receive Payment.
3. Select the name of the customer from the drop-down menu.
4. From the Outstanding Transactions section, select the transactions that you’d like for QuickBooks Online to calculate. As you select these items, the payment total will change.
5. Select the payment method.
6. Enter the Reference no. and Memo if applicable.
7. You can either deposit the money to your checking account or to the Undeposited funds account.
8. Select Save and close.

Also, you can review this article as your reference on how to put your payments into the Undeposited Funds account before you combine them into a deposit in QBO: Deposit payments into the Undeposited Funds account in QuickBooks Online.

Let me know if you have other questions.