To add opening balance as Due while adding new customer, please follow the below mentioned steps,
Step 1. Click on Parties from the home page.
Step 2. Select Customers and click on + New Customers.
Step 3. Enter the Customer Details and Scroll Down.
Step 4. Click on Arrow next to Other Details, and click on Opening Balance.
Step 5. Record the payment as Debit and click on Add Opening Balance.
Step 6. Click on Add Customer.
Now your new Customer is added with Payment Due.





