Hi there, cmrdgrs.
The auto-fill feature for email templates is unavailable in QuickBooks Desktop. You'll have to add the amounts manually when sending reminders about remaining balances to your customers.
Since there isn't a direct way to auto-fill partial payment information in email templates, you can use these features in combination to manage partial payments and communicate with customers effectively. You need to customize it manually the email content when sending.
I will include this article so that you can learn how to customize email templates and use them to send messages from QuickBooks: Create custom email templates in QuickBooks Desktop.
You may visit this if you want to split an estimate into as many invoices as you need. This way, you can invoice customers for partial payments: Set up and send progress invoices in QuickBooks Desktop.
Let me know if you still need help with QuickBooks. I'm here to help whenever you need me. All the best!
