Ind. Code § 6-6-6.5-14
(c) When a taxpayer makes a partial payment on the taxpayer's tax liability, the department shall apply the partial payment in the following order:
(5) To any gross retail or use tax owed by the taxpayer.
Formerly: Acts 1975, P.L.68, SEC.1. As amended by Acts 1977, P.L.87, SEC.8; P.L.93-1983, SEC.9; P.L.65-1997, SEC.18.