Hi there, laurietilelli.
I'm glad you've reached out to the QuickBooks Community. Let me help share some insights about the customer statement in QuickBooks Desktop.
The customer statement only shows the summary of your customer's account, listing recent invoices, credit memos, and payments received. To check which invoice payment was applied to, you'll need to pull up the Transactions List by Customer report.
Let me walk you through the steps:
You can also check this article on how to customize reports in QuickBooks Desktop.
For additional reference, you can check this article: Create a billing statement.
If you need further assistance with the steps, I recommend to contact our QuickBooks Desktop Support Team. They have additional tools to pull up your account and do a remote session.
Here's how you can contact our customer support:
That should do it! Feel me in if you have additional questions about the customer statement. I'm always here to help. Wishing you and your business continued success.