| Form 1CNS | Tax-option(s) corporations having two or more qualifying nonresident shareholders may file a composite return to report and pay the Wisconsin income tax owed by those shareholders. | |
| Form 4 | Corporations (other than tax-option corporations) report under the non-combined or separate accounting methods. | 4BL, 4I, 4V, 4W, 4Y, 9B, A-1, A-2, BD, C, CF, CM, CR, CU, CU-1, DC, DE, EC, ED, FC, FC-A, HR, HR-T, JT, MA-A, MA-M, MI, MS, N, R, RT, RT-1, TC, U, VC |
| Form 4466W | Wisconsin Corporation or Pass-Through Entity Application for Quick Refund of Overpayment of Estimated Tax | |
| Form 4H | Corporations that have been completely inactive in and outside Wisconsin for the entire taxable year and don't anticipate any activity in future years. No other return is required until a corporation is activated, reactivated, or requested to file by the Department of Revenue.
Note: Foreign corporations licensed to transact business in Wisconsin that have no property or activity in Wisconsin but are active outside Wisconsin may not file Form 4H. They must file Form 4 or 5S but need only check box F "No business transacted in Wisconsin" on the front of the return and attach a copy of their federal return. | |
| Form 4T | Exempt corporations and associations of individuals that have unrelated business taxable income as defined in Internal Revenue Code (IRC) section 512. | A-1, A-2, 9B, BD, CF, CM, CR, DC, DE, EC, ED, FC, FC-A, HR, HR-T, JT, MA-A, MA-M, MI, MS, N, R, RT, RT-1, TC, U, VC |
| Form 5E | Corporations that have elected and qualified to be S corporations for federal tax purposes but are electing not to be tax-option corporations for Wisconsin franchise or income tax purposes. In addition, such corporations must file Form 4 or 6. | |
| Form 5R | Federal S corporations that elected not to be tax-option corporations for Wisconsin and subsequently are revoking their "opt-out" elections. In addition, such corporations must file Form 5S. | |
| Form 5S | Tax-option (S) corporations | 1CNS, 5K-1, 9B, A-1, A-2, BD, CM, DC, DE, EC, ED, HR, HR-T, JT, MA-A, MA-M, MI, MS, N, PW-1, PW-2, PW-ES, PW-U, R, RT, RT-1, TC, U, VC |
| Form 6 | Wisconsin Combined Corporation Franchise or Income Tax Return | 6BL, 6CL, 6CS, 6I, 6Y, 9B, A-1, A-2, BD, C, CF, CM, CU, CU-1, DC, DE, EC, ED, FC, FC-A, HR, HR-T, JT, MA-A, MA-M, MI, MS, N, R, RT, RT-1, TC, U, VC |
| Form CU | Credit unions that don't act as a public depository for state or local government funds. These credit unions are exempt from taxation by Wisconsin. Once a Form CU has been filed, no other return must be filed unless requested by the Department of Revenue or the credit union subsequently acts as a public depository. | |
| Form HR-T | Transfer of Supplement to Federal Historic Rehabilitation Credit | |
| Form PW-1 | Tax-option(s) corporations having at least one nonresident shareholder whose share of distributable income allocable from the corporation is $1,000 or more. | PW-ES, PW-U |
| Form PW-2 | Nonresident shareholders use Form PW-2 to claim exemption from Wisconsin's withholding tax on income from pass-through entities. | |
| Form PW-ES | Wisconsin Pass-Through Entity Withholding Estimated Tax Voucher | |
| Form PW-U | Underpayment of Estimated Withholding Tax by Pass-Through Entities | |
| Form WR-A | Required attachment for E-filing and instructions | |