Indiana Code Title 36. Local Government § 36-7-13-14

Sec. 14. (a) Before the first business day in October of each year, the department shall calculate the income tax incremental amount and the gross retail incremental amount for the preceding state fiscal year for each district designated under this chapter.

(b) Businesses operating in the district shall report annually, in the manner and in the form prescribed by the department, information that the department determines necessary to calculate incremental gross retail, use, and income taxes.  A taxpayer operating in the district that files a consolidated tax return with the department also shall file annually an informational return with the department for each business location of the taxpayer within the district.  If a taxpayer fails to report the information required by this section or file an informational return required by this section, the department shall use the best information available in calculating the incremental gross retail, use, and income taxes.

(c) Not later than sixty (60) days after receiving a certification of a district's modified boundaries under section 12.5(c) of this chapter, the department shall recalculate the income tax incremental amount and the gross retail incremental amount for the preceding state fiscal year for a district modified under section 12.5 of this chapter.