Ind. Code § 22-4-29-3
The commissioner, or the commissioner's duly authorized representative, shall immediately notify the employing unit of the assessment in writing by mail, and such assessment shall be final unless the employing unit protests such assessment within fifteen (15) days after the mailing of the notice.
Formerly: Acts 1947, c.208, s.3003. As amended by P.L.20-1986, SEC.14; P.L.18-1987, SEC.77; P.L.21-1995, SEC.112.