The amount of commission to a financial institution is less than I invoiced my customer. How do I give the left over amount in the bank transaction back to customer?

It's nice to have the chance to address your concern for today, userkiff_geoffrey.

You can process a refund back to your customer's bank using the Refund receipt feature. Here's how to refund an invoice your customer already paid for.

1. Go to + New.
2. Choose Refund receipt.
3. Select the customer you want to refund from the Customer dropdown.
4. Enter the details in the fields using the info from the original sale.
5. Select which payment method and account you wish to refund the customer from.
6. Click Save and close.

Learn more about the process of refunding customer payments in QBO through this article: Void or refund customer payments in QuickBooks Online.

To review the Refund receipts you've created, you might want to run the Transaction List by Customer report, and customize it to show all the refund receipts that you've processed.

Here's how:

1. Go to the Reports menu at the left panel, then type Transaction List by Customer on the search bar.
2. Click Customize on the upper right.
3. On the General drop-down, select the appropriate date on the Report period.
4. Now go to the Filter drop-down and choose Refund on the Transaction Type drop-down.
5. Pick a specific customer on the Customer drop-down, then Run report.

Just in case, you can also check out this article for future reference: How to customise reports.
 

You might also want to visit our QuickBooks Online learning guides for tutorials and webinars about the product.

Drop me a reply if you have other questions managing invoices. I'm always happy to assist you further. Have a great day ahead.