When I select Add Payment on an invoice, it doesn't associate the payment with that invoice. The invoice still shows as being overdue.

Hello smarttreececare-ou,

It's great to have you reach out to us here. I'll be happy to share more info so you're on the right track with achieving your QuickBooks goals. 

Here's how to apply the payment to the invoice: 

1. Click the +New button
2. Select Receive payment
3. Enter the name of the customer or select Find by invoice no. and enter the invoice number
4. Fill in the following:
   • Payment date
   • Payment method
   • Reference no. (optional)
   • Deposit to
   • Amount Received
5. Under Outstanding Transactions select the invoices the payment applies to
6. Click Save and Close. 

I encourage you to try this and let me know what happens. I'll be a message away in case you have other questions.