Indiana Code Title 6. Taxation § 6-3-8.1-3

Sec. 3. (a) The supplemental net income tax imposed under IC 6-3-8 (repealed) for that taxable year is equal to the result determined under STEP TWO of the following formula:

STEP ONE:  Determine the product of the taxpayer's net income for the taxpayer's regular taxable year multiplied by a tax rate equal to four and five-tenths percent (4.5%).

STEP TWO:  Multiply the STEP ONE result by a fraction, the numerator of which is the number of days in the taxpayer's taxable year that occurred before January 1, 2003, and the denominator of which is the total number of days in the taxable year.

(b) The department of state revenue may prescribe forms and procedures for reconciling:

The procedures may include procedures for granting an automatic extension for the filing of some or all returns that were due before April 16, 2003, under P.L.192-2002(ss), SECTION 197, before the enactment of P.L.269-2003, SECTION 13.