Hi there,
Thanks for joining us here in the Community. I'll be happy to share more info about using QuickBooks so you can continue to manage your customers with peace of mind.
The good thing about using QuickBooks is that once an invoice is paid, the program automatically marks the invoice is paid. It's important to note that you'd first have to record the invoice payment in order for it to show as paid. Here's a helpful article that shows you how to: Record invoice payments in QuickBooks.
In case you'd like to customize the way your invoices or other sales form appear to your customers, I encourage you to check out the following article that shows you how to: Customize sales forms in QuickBooks.
Let me know if this info helps. I'll be one message away in case you need anything else.
