Hi joseph30,

Welcome to Community!  I can see how having the ability to add blank lines to the invoices would be beneficial, in providing a clear picture of your business from a professional standpoint.  QuickBooks Online is a powerful program for managing your daily tasks with ease.  I'd be happy to assist!

Currently, there's no in product feature for adding line breaks to your invoices.  As an alternative, I suggest spacing your line items by adding a blank row between them.  This will make the invoice cleaner and you'll see the result on the print/preview screen.

If you have any other questions, please feel free to reach back out.  We'd be glad to help!