How to apply a bank charge to a client invoice after payment, due to an incorrectly filled out check.

I’ll make sure you’ll be able to apply the additional check payment, @SRH2658.

To apply the additional $400 check payment, Let's create a service fee item and add it to the existing invoice to charge the client accordingly. I'll guide you through the steps.

To create a service fee item, here's how:

1. Click on the Gear icon in the upper left and select Products & Services.
2. Choose New, and then select Service.
3.  Enter a name for the service in the Name field.
4. Select Save and Close.

Once done, add a service fee to the invoice. 

I'll show you how:

1. Navigate to Sales and then click on Invoices.
2. Choose the invoice to which you want to add a service fee.
3. Click on Edit Invoice.
4. From the Product or Service dropdown, select the service fee you created.
5. In the Amount field, enter the amount of the service fee.
6.  In the Note to Customer section, include a note about the fee.
7. Finally, select Review and Send.

You can also read this article for the complete details: Manually add service fees to invoices in QuickBooks Online.

Furthermore, I've included an article that guides personalizing and adding specific information to your sales forms: Customize invoices, estimates, and sales receipts in QuickBooks Online.

You're more than welcome to drop by again if you have concerns about managing customer payments and refunds. I'll also help you out if you have questions about other entries or when running reports. Always here to help.