You can set up the unique MID when there are no profiles created in the Practice Preferences window.
Open NextGen® Enterprise PM
Select Admin > Preferences > User > General.
Select the Payment Processing tab.
Enter Swipe MID, Terminal ID, Non-Swipe, and Store ID provided by NextGen® Pay powered by InstaMed.
The Swipe MID and Terminal ID numbers are attached to all credit card transactions when the card is not present or when the number is keyed into the system. If Terminal ID and Store ID are left blank, the application fills the field with 0001.