In a oral response to a consumer's inquiry about the cost of closed-end credit, only the annual percentage rate shall be stated, except that a simple annual rate or periodic rate also may be stated if it is applied to an unpaid balance. If the annual percentage rate cannot be determined in advance, the annual percentage rate for a sample transaction shall be stated, and other cost information for the consumer's specific transaction may be given.
Okla. Admin. Code § 160:15-2-6