Article Link: http://help.truecommerce.com/en/articles/5605324-nexternal-billing-methods-by-customer-type
In the Nexternal Order Management System (OMS), billing options include Credit Card, ACH, Invoice, Paypal, COD and up to two custom methods that can be defined by the merchant.
For merchants who service multiple customer types via a single Nexternal account, it's easy to customize the user experience by assigning different billing options to different customer types. For example, a merchant may want to offer consumers the options to pay only via credit card or Paypal, but they may want wholesale customers not to have the credit card and/or Paypal options, but instead to have either an invoice option or an ACH option.
Billing options are set up in Settings / Billing Options. Each of the billing options can be assigned to customer types by Rank, or, using the overrides, by customer type.
For each form of payment that you accept, you must enter the minimum customer Rank (Customers/Types) required to make that option available; you may also override the minimum Rank (to either Allow or Deny) for specific Customer Types via the Set Overrides button.
Once you've set up your billing options simply click finish at the bottom of the page, and you're all set.