How to add a payment code to Sage 300 Accounts Payable Steps: Open Accounts Payable>A/P Setup>Payment Codes.In the Payment Code field, type an identifying code, using up to six characters, and then press the Tab key.Type a description for the payment code, such as the name of the credit card.For the payment type, select Cash, Check, Credit Card, or Other.Click Add. Support If necessary, seek the assistance of Acute Data Systems to help provide assistance with this process. Sage 300 Request Support