For each customer account you need to setup the payment terms and credit limits associated with the customer account.

Payment Terms – The payment terms is a drop down list. Select the payment terms you have for this customer account.  If you do not see the payment terms you want, simply double click in the yellow box area of payment terms to open the maintain payment terms screen to add another payment terms option:

Credit Limit – Enter the credit limit amount you will extend to this customer.  If the customer exceeds their credit limit on an order, a warning window will pop up telling you that the order cannot be direct billed as they have exceeded their credit limit.