Some billers in NATS allow your members to perform up sales, which allows your members to upgrade their account to a more expensive option on your join form. This can be configured through the Cross/Up Sales Admin.
The following text provides a list of all billers who support cross-sales in NATS and a link to their biller-specific wiki article.
For more information on configuring an Up Sale in NATS, please see "Up Sales."
