(1)    Except as provided in sub. (2), any county may impose county sales and use taxes under this subchapter by the adoption of an ordinance, stating its purpose and referring to this subchapter. The rate of the tax imposed under this subsection is 0.5 percent of the sales price or purchase price. Except as provided in s. 66.0621 (3m), the county sales and use taxes imposed under this subsection may be imposed only for the purpose of directly reducing the property tax levy and only in their entirety as provided in this subchapter. That ordinance shall be effective on January 1, April 1, July 1, or October 1. A certified copy of that ordinance shall be delivered to the secretary of revenue at least 120 days prior to its effective date. The repeal of any such ordinance shall be effective on December 31. A certified copy of a repeal ordinance shall be delivered to the secretary of revenue at least 120 days before the effective date of the repeal. Except as provided under s. 77.60 (9), the department of revenue may not issue any assessment or act on any claim for a refund or any claim for an adjustment under s. 77.585 after the end of the calendar year that is 4 years after the year in which the county has enacted a repeal ordinance under this subsection.

   (2)   

      (a)    In addition to the taxes imposed under sub. (1), a county in which a 1st class city is located may adopt an ordinance, by a two-thirds majority vote of all members elect of the county board, to impose sales and use taxes under this subchapter at the rate of 0.4 percent of the sales price or purchase price. An ordinance adopted under this subsection shall be effective on January 1, April 1, July 1, or October 1 and the taxes shall be imposed only in their entirety as provided in this subchapter. A certified copy of the ordinance shall be delivered to the secretary of revenue at least 120 days prior to its effective date. No county may impose a tax under this subsection unless the county makes an election to join the Wisconsin Retirement System for all new employees, pursuant to s. 40.21 (7) (a), and the county contributes the amount calculated under s. 59.875 (4) to its retirement system’s unfunded actuarial accrued liability from the taxes imposed under this subsection in 2025 and in each year thereafter until the first year in which the retirement system is determined by the retirement system’s actuary to be fully funded. After the retirement system is first fully funded, or December 31, 2050, whichever is earlier, the actuary shall determine all future required contributions from the county on the basis of standard actuarial practices, and the county shall repeal the ordinance imposing the tax. A certified copy of that ordinance shall be delivered to the secretary of revenue at least 120 days prior to its effective date. The repeal of any such ordinance shall be effective on December 31. A certified copy of a repeal ordinance shall be delivered to the secretary of revenue at least 120 days before the effective date of the repeal. Except as provided under s. 77.60 (9), the department of revenue may not issue any assessment or act on any claim for a refund or any claim for an adjustment under s. 77.585 after the end of the calendar year that is 4 years after the year in which the county has enacted a repeal ordinance under this subsection.

      (b)    Annually, after making the required payment to its retirement system’s unfunded actuarial accrued liability under par. (a), the county shall use the remaining revenues received under this subsection for any of the following:

         1m.    Payments for its pension bond obligations.

         2m.    Additional payments for its retirement system’s unfunded actuarial accrued liability.

         3m.    Payments for its employer contribution to a retirement system established under chapter 201, laws of 1937.

      (c)    Annually, beginning in 2026, the county shall submit a report to the joint committee on finance, in the manner provided under s. 13.172 (2), containing detailed information on the county’s expenditures in the previous year from the revenues collected under this subsection.