Assigning different invoice number automatically for each customer is currently unavailable. As a workaround, you can enter your desired invoice number manually. To do so, let’s activate the future to use custom transaction numbers. Here’s how:
Click The Gear icon at the top.
Select Custom Form Styles.
Click Edit on the template you’re currently using.
Go to the Content tab.
Click the header part of the template.
Select Use custom transaction numbers under Form.
Please let me know if you have other questions about QuickBooks.