Setting all new customers you create to be on account is controlled by a permission.
- Visit Maintain->System Admin->User Group
- Select the user group you wish to Edit
*you will need to enable this permission on each user group that creates customer files
- Expand out the section "3.00.000 Maintain Card File"
- enable the permission "3.10.135 On account customer always selected"
*You may also wish to disable "3.10.130 Allow to change a customers On Account status" to ensure users can not modify this status.
- click "OK" at the bottom of the page
All new customers you create will now be set as On account customers.