By default, the Secure Payment application's payment module automatically assigns an invoice number for each transaction processed. You cannot process a transaction without an invoice number, which then appears on the transaction receipt. You can choose to disable automatic invoice numbering but the terminal will prompt the operator to input an invoice number manually (with a maximum of 12 numeric characters).
From the main screen, touch Settings.
Enter the merchant password and touch Confirm.
Scroll to the Configure application section.
Touch Terminal options.
Scroll to the General section.
Enable the use of automatic numbering by toggling the Automatic invoice number switch to the right.
Disable the use of automatic numbering the Automatic invoice number switch to the left.
If you have more than one terminal, repeat steps 1 to 7 for each additional terminal where you want automatic or manual invoice numbering.