Ind. Code § 6-8.1-5-4 – Books and records; federal returns; inspection

(a) Every person subject to a listed tax must keep books and records so that the department can determine the amount, if any, of the person's liability for that tax by reviewing those books and records. The records referred to in this subsection include all source documents necessary to determine the tax, including invoices, register tapes, receipts, and canceled checks.
(b) A person must retain the books and records described in subsection (a), and any state or federal tax return that the person has filed:
1. (1) for an unlimited period, if the person fails to file a return or receives notice from the department that the person has filed a suspected fraudulent return, or an unsigned or substantially blank return; or
2. (2) in all other cases, for a period of at least three (3) years after the date the final payment of the particular tax liability was due, unless after an audit, the department consents to earlier destruction.
  In addition, if the limitation on assessments provided in section 2 of this chapter is extended beyond three (3) years for a particular tax liability, the person must retain the books and records until the assessment period is over.
(c) A person must allow inspection of the books and records and returns by the department or its authorized agents at all reasonable times.
(d) A person must, on request by the department, furnish a copy of any federal returns that he has filed.
As added by Acts 1980, P.L.61, SEC.1. Amended by P.L.6-1987, SEC.11; P.L.71-1993, SEC.18.