Ind. Code § 6-9-41-8

Sec. 8. If an ordinance is not adopted under section 9 of this chapter, the tax that may be imposed under section 5 of this chapter shall be imposed, paid, and collected in the same manner that the state gross retail tax is imposed, paid, and collected under IC 6-2.5. However, the return to be filed for the payment of the tax under this chapter may be made separately or may be combined with the return filed for the payment of the state gross retail tax, as prescribed by the department of state revenue.