Indiana Code Title 6. Taxation § 6-3.5-11-11

Sec. 11. (a) An owner of one (1) or more commercial vehicles paying an apportioned registration to the state under the International Registration Plan that is required to pay a wheel tax shall pay an apportioned wheel tax calculated by dividing in-state actual miles by total fleet miles generated during the preceding year.  If in-state miles are estimated for purposes of proportional registration, these miles are divided by total actual and estimated fleet miles.  The apportioned wheel tax under this section shall be paid at the same time and in the same manner as the commercial vehicle excise tax under IC 6-6-5.5.

(b) A voucher from the department showing payment of the wheel tax may be accepted by the bureau of motor vehicles instead of the payment required under section 10 of this chapter.