Great to have you here, Agnes.
I appreciate you checking in with us. Helping out with charging the overdue invoices is my priority.
You can charge an interest to an overdue invoices by adding a finance charge to the transaction. First, we need to create an item for the finance charge.
After creating an item, let's open the overdue invoices and add the finance charge item that you've set up. Next, you'll need to enter the finance charge amount and click Save and close.
This helps you apply a charge interest on the overdue invoices in QBO. Please know that I'm just a post away if you need anything else. Wishing you continued success.