WI AB870

Updates Wisconsin's definition of "Internal Revenue Code" from December 31, 2022 to December 31, 2025 for state income and franchise tax purposes, affecting individuals, fiduciaries, corporations, and tax-option corporations

Excludes specific federal public law provisions from Wisconsin's adoption of the IRC, including sections related to qualified business income deductions, international tax provisions, and various COVID-era relief measures

Modifies reporting thresholds for non-wage payments, rents, and royalties from a fixed $600 to the dollar amount in effect under IRC section 6041(a) for the applicable calendar year

Updates Department of Revenue administrative rules to replace Wisconsin Form 9b with federal forms 1099-MISC and 1099-NEC for reporting compensation, rents, and royalties

Creates provisions requiring income adjustments to prevent double inclusion or omission of items due to state and federal tax code differences, including basis differences, depreciation methods, and transitional adjustments