Hello pepito,

There are different ways to record a customer refund in QuickBooks Online. The steps may differ depending on your scenario. You can create one of the following:

• Credit Memo - you can use it as payment for other invoices of the customer.
• Refund Receipt - this a reimbursement to the customer for the returned items.
• Check - this will reduce your bank's balance and offset the customer's open credits.

Though, you're more-likely to create a check based on the details you provided, I'd still recommend reaching out to your accountant about this. They know the best way to record it.

You can also browse the Refund a customer for open credit, prepayment, or over payment section of this link: Record a Customer Refund.

To return the actual amount to your customer, you might still need to ask for their credit card information. Then, you send the money through bank transfer or ACH.

Have a great day!