Administration.

For taxable years beginning after December 31, 2017, s. 71.28 (4) (b) to (e), (g), and (h), as it applies to the credit under s. 71.28 (4), applies to the credits under this subsection. For taxable years beginning after December 31, 2017, if the allowable amount of the claim under par. (b) 4., 5., or 6. exceeds the tax otherwise due under s. 71.02, all of the following apply: a. For taxable years beginning before January 1, 2021, the amount of the claim not used to offset the tax due, not to exceed 10 percent of the allowable amount of the claim under par. (b) 4., 5., or 6., shall be certified by the department of revenue to the department of administration for payment by check, share draft, or other draft drawn from the appropriation account under s. 20.835 (2) (d). For taxable years beginning after December 31, 2020 and before January 1, 2024, the amount of the claim not used to offset the tax due, up to 15 percent of the allowable amount of the claim under par. (b) 4., 5., or 6., shall be certified by the department of revenue to the department of administration for payment by check, share draft, or other draft drawn from the appropriation account under s. 20.835 (2) (d). ad. For taxable years beginning after December 31, 2023, the amount of the claim not used to offset the tax due, not to exceed 25 percent of the allowable amount of the claim under par. (b) 4., 5., or 6., shall be certified by the department of revenue to the department of administration for payment by check, share draft, or other draft drawn from the appropriation account under s. 20.835 (2) (d). b. The amount of the claim not used to offset the tax due and not certified for payment under subd. 2. a. or 2. ad. may be carried forward and credited against Wisconsin income taxes otherwise due for the following 50 taxable years to the extent not offset by these taxes otherwise due in all intervening years between the year in which the expense was incurred and the year in which the carry-forward credit is claimed.