You've noticed a clients Account Balance or Overdue Balance appears incorrect.
Why is this problem occurring
A problem has happened with the interface and the values have not refreshed correctly.
To refresh the values here's what we need to do:
1. Create a new project for the affected client.
2. Create a slip for the project and mark it Done. (the value can be $0.00)
3. Invoice the slip. Now you should now see the client's balance has been refreshed and showing the correct amount.
4. You can now delete this invoice and the project.
Note: By creating and deleting the invoice your account's next invoice number has advanced by one. You can go into your Billings Pro Preferences and change the next invoice number back by one number in the "Numbering" pane.