Does registering an external user (supplier) of the iSupplier portal require an iSupplier license?

Greetings,

Would every registered supplier type of user of the iSupplier 12.2.5 portal require a separate iSupplier user license? Our client has a large supplier base, and buying a license for each and every potential iSupplier external user account would be prohibitively costly.

Our client is considering buying a perpetual license for a number of application users.

"Application User: is defined as an individual authorized by you to use the applicable licensed application programs which are installed on a single server or on multiple servers regardless of whether the individual is actively using the programs at any given time."

Does the "application user" definition apply only to individual internal users, and not the external users/organizations? Oracle sometimes doesn't require a license for external users, i.e. vendors, to access certain modules.