An account customer's invoices are coming up as being immediately due.

How do I correct this?

1. Change the customer's Trading Terms

Go to the Database, find the customer, select the "Customers" tab > Terms of Trade > Default button on dialog

Change the Terms of Trade to suit

This change will take effect on any new Invoice. Any existing invoices will need to be edited.

If closed they will need to be opened

Edit the header to suit the terms of trade