2.10 Copies of federal returns, statements,

schedules, documents, etc. to be filed with Wisconsin returns. (1) INDIVIDUALS AND FIDUCIARIES. At the time of fil- ing Wisconsin income tax returns by individuals and fiduciaries, a complete copy of the federal income tax return for the same tax- able year, including all schedules, statements, documents and computations which affect the computation of Wisconsin in- come, credits or penalties, shall be included and filed with the Wisconsin return. If the federal form is filed electronically, a copy of the electronic material as contained in replicas of the of- ficial forms or on forms designated by the electronic filer shall be included and filed with the Wisconsin return. (2) PARTNERSHIPS AND LIMITED LIABILITY COMPANIES TREATED AS PARTNERSHIPS. (a) Except as provided in par. (b), at the time of filing Wisconsin income tax returns by partnerships and limited liability companies treated as partnerships under s. 71.20 (1), Stats., a complete copy of the federal income tax return for the same taxable year, including all schedules, statements, documents and computations which affect the computation of Wisconsin income, deductions and credits, shall be included and filed with the Wisconsin return. If the federal form is filed elec- tronically, a copy of the electronic material as contained in repli- cas of the official forms or on forms designated by the electronic filer shall be included and filed with the Wisconsin return. (b) Copies of the federal schedules K-1 are not required to be filed for those partners or members for whom a Wisconsin sched- ule 3K-1 is being filed for the same taxable year. A Wisconsin schedule 3K-1 shall be filed in lieu of federal schedule K-1 for a partner or member if any of the following applies: 1. The computation of the Wisconsin income or deductions differs from the federal amount. 2. The partner or member is a nonresident of Wisconsin or part-year resident of Wisconsin and the partnership or limited lia- bility company has activities within and without Wisconsin. 3. The partnership or limited liability company calculates any Wisconsin income tax credits. Note: Section Tax 2.10 interprets ss. 71.03 (5) and 71.20 (1), Stats. History: Register, December, 1965, No. 120, eff. 1-1-66; am. Register, June, 1990, No. 414, eff. 7-1-90; r. and recr. Register, May, 1995, No. 473, eff. 6-1-95: CR 21-085; am. (1) Register August 2022 No. 800, eff. 9-1-22.