Okay, so I wrongly created a journal entry for a "payment" which was for offsetting customer's invoice to us, against invoices customer owed us?

Hi, @accounts530. 

You can delete the wrongly created journal entry to rectify your record. I'll guide you on how.

1. Sign in to your QuickBooks Online (QBO) account.
2. Click on Reports on the left pane.
3. Search for Journal, then open the report.
4. Select the journal entry created.
5. Tap on More, then Delete.

Moving forward, you can record an invoice payment following the steps provided from this link: Record invoice payments in QuickBooks Online.

When your customer pays his/her outstanding balance, you can record and make a deposit.

If you wish to recreate the journal entry, use the correct debit and credit accounts to avoid issues.

On the other hand, you can get more tips while handling your invoices and other customer entries from our self-help articles:

• Add, organise, and send invoices
• Topics about your company's income and customers

Let me know if you have any other questions about your invoices and payments. I'm always here to help. Have a good one!