Hi there, gmplastering2001. I am here to guide you through processing a refund and adjusting the invoice in QuickBooks Online (QBO) for a customer who paid with a check.
To begin, create a check or expense linked to Accounts Receivable (A/R) that will document the refund. The purpose of choosing A/R for the outgoing refund is to associate it with the initial invoice payment. Proceed with the following steps:
- Go to the +New button. Then, select Check or Expense.
- From the Payee drop-down list, pick the customer you intend to give the refund.
- Choose the appropriate bank account from the Bank Account dropdown.
- Select the Payment date.
- From the Category section, choose Accounts Receivable.
- Enter the refund amount in the Amount field.
- Review other details. Then, click Save and close.

Next, we'll have to navigate to the customer profile and locate the original invoice payment. In this part, we'll have to unlink the payment from the original invoice and link it to the check/expense we've recently created. So that your invoice will be open, and can be send to your customers. Here's how:
- Navigate Sales, and then, Customers.
- Click on the customer profile and locate the original invoice payment from the Transaction List tab.
- Select View/Edit.
- Uncheck the payment from the original invoice and place a checkmark on the recently created check or expense.
- Select Save and Close.

I included this article to gain further insights on how to record a customer's bounced check as an expense in QuickBooks Online: Record a returned payment or bounced check in QuickBooks Online.
Refer to this article for guidance on how to customize and include specific details on your sales forms: Customize invoices, estimates, and sales receipts in QuickBooks Online.
If you encounter any questions while adjusting your invoice, please leave a comment below. We're here to support you and make the process seamless. Take care!