Use an invoice any time you bill your customers for payment.
You can bill your customers for an entire project or for portions of a project.
You can use both invoices and sales receipts for your customers. You can also use any other combination
of QuickBooks sales forms, such as estimates, statements, or sales receipts. Based on how you do business with your customers,
you can use just one of these forms or you can use all of them.
Not sure which QuickBooks form you need? Answer the questions in the EasyStep Interview based on how you
do business with your customers. QuickBooks will recommend the appropriate form(s) to use.