I have 3 invoices that will never pay so how do I write them off?

Good to see you here, nigel3.

I've got some steps on how you can write off the invoices.

First, you'll need to create a bad debt expense account in the Chart of Accounts. Then, add a bad debt item by following these steps:

1. Click the Gear icon located in the upper right-hand corner.
2. Under Lists, click Products and Services.
3. Select New, and then choose Non-inventory.
4. Enter “Bad debts" in the Name field.
5. Select the bad debts account we created from the Income account drop-down menu.
6. Click Save and Close.

Once done, our next step is to create a credit note for the bad debt. Then, apply the credit note to the invoice by following these steps:

1. Click the Create (+) icon, and select Receive Payment under Customers.
2. Select the customer's name from the Customer drop-down menu.
3. Select the invoice from the Outstanding Transactions section, and put a check mark on the credit note that shows under Credits.
4. Click Save and Close.

Here's a sample screenshot for reference:

Finally, go to the Chart of Accounts page and run a report for the bad debt account.

You can open this article for the detailed steps: Write off bad debt.

I'm always around if you need more help with QuickBooks Online. Thanks.