Writing off an invoice as bad debt clears it from your accounts receivable and records the loss as an expense.
Since you've identified the specific invoice that won't be paid, you can follow steps 2-5 in this article to clear it from your books: How to write off bad debt in QuickBooks Online.
It's a good idea to check in with your accountant before you finish this process. They can let you know exactly how this change affects your specific financial records.
Have more questions? Drop a reply below.