You can send them a statement, Artie C.

Create a statement to itemize all open invoices, credit memos, and payments received from your customers. Here's how:

1. Click the Customers menu and select Create Statements. 
2. Select the Statement Date and the date range. 
3. From the Select Customers section, select One Customer and select the specific customer.
4. Select addition options and then click Preview.
5. Click Print.

You can use this link for more details about customer transaction workflows in QuickBooks Desktop.

Let me know if you have other questions. Take care and have a great day!