Ind. Code § 6-1.1-16-2

Sec. 2. (a) If a county property tax assessment board of appeals fails to change an assessed value claimed by a taxpayer on a personal property return and give notice of the change within the time prescribed in section 1(a)(2) of this chapter, the township assessor, or the county assessor if there is no township assessor for the township, may file a petition for review of the assessment by the Indiana board. The township or county assessor must file the petition for review in the manner provided in IC 6-1.1-15-3(d). The period for filing the petition begins to run on the last day that the county board is permitted to act on the assessment under section 1(a)(2) of this chapter as though the board acted and gave notice of its action on that day.