(1) Any taxpayer required to make a return for a taxable year under this code may, at any time that a deficiency could be assessed or a refund claimed under this code in respect of any item reported or properly reportable on such return or any amendment thereof, be required to furnish to the department a true and correct copy of any return which may pertain to such item and which was filed by such taxpayer under the provisions of the Internal Revenue Code.
(2) In the event the taxable income, any item of income or deduction, or the income tax liability reported in a federal income tax return of any taxpayer for any taxable year is adjusted by amendment of such return or as a result of any other recomputation or redetermination of federal taxable income or loss, if such adjustment would affect any item or items entering into the computation of such taxpayer’s net income subject to tax for any taxable year under this code, the following special rules shall apply: (a) The taxpayer shall notify the department of such adjustment by filing either an amended return or such other report as the department may by regulation prescribe, which return or report:
1. Shall show the taxpayer’s name, address, and employer identification number; the adjustments; the taxpayer’s revised net income subject to tax and revised tax liability under this code; and such other information as the department may by regulation prescribe;
2. Shall be signed by a person required to sign the original return or by a duly authorized representative; and
3. Shall be filed not later than 60 days after such adjustment has been agreed to or finally determined for federal income tax purposes, or after any federal income tax deficiency or refund, abatement, or credit resulting therefrom has been assessed, paid, or collected, whichever shall first occur.
(b) If the amended return or other report filed with the department concedes the accuracy of a federal change or correction, any deficiency in tax under this code resulting therefrom shall be deemed assessed on the date of filing such amended return or report, and such assessment shall be timely, notwithstanding any other provision contained in part VIII of this chapter.
(c) In any case where notification of an adjustment is required under paragraph (a), then notwithstanding any other provision contained in s. 95.091(3):
1. A notice of deficiency may be issued at any time within 5 years after the date such notification is given; or
2. If a taxpayer either fails to notify the department or fails to report a change or correction which is treated in the same manner as if it were a deficiency for federal income tax purposes, a notice of deficiency may be issued at any time;
3. In either case, the amount of any proposed assessment set forth in such notice shall be limited to the amount of any deficiency resulting under this code from recomputation of the taxpayer’s income for the taxable year after giving effect only to the item or items reflected in the adjustment.
Interest in accordance with s. 220.807 is due on the amount of any deficiency from the date fixed for filing the original return for the taxable year, determined without regard to any extension of time for filing the original return, until the date of payment of the deficiency.
(d) In any case when notification of an adjustment is required by paragraph (a), a claim for refund may be filed within 2 years after the date on which such notification was due, regardless of whether such notice was given, notwithstanding any other provision contained in s. 220.727. However, the amount recoverable pursuant to such a claim shall be limited to the amount of any overpayment resulting under this code from recomputation of the taxpayer’s income for the taxable year after giving effect only to the item or items reflected in the adjustment required to be reported.