Knowing how to best record this kind of transaction depends on how you recorded the transaction initially. It sounds like you've sent a payment to a vendor, which could be recorded in QuickBooks as an expense or bill payment, depending on the transaction. In this case, it may be as simple as voiding the expense or bill payment to show that the payment was not received by the recipient. On an expense, just open the transaction and then click the downward arrow below Delete and choose Void. Follow these steps to void a bill payment.
Go to the Chart of Accounts (Note: CTRL + A is a great shortcut for this).
Double click to open the Accounts Payable register.
Find the bill payment.
Highlight the bill payment then go to the Edit menu in the toolbar and choose Void Bill Pmt.
That's all it takes. Feel free to check in with your accountant to confirm that voiding the payment is the way to go.