Ind. Code § 6-8.1-15-9

Sec. 9. As used in this chapter, "prepaid telephone calling service" means the right to purchase exclusively telecommunications service that must be paid for in advance that enables the origination of calls using an access number or authorization code, or both, whether manually or electronically dialed, if the remaining amount of units of service that has been prepaid is known by the provider of the prepaid service on a continuous basis.