Form5S: Wisconsin Tax-Option (S) Corporation Franchise or Income Tax Return (2024)
Wisconsin · Wisconsin DOR · Used for tax years 2024
Form 5S is Wisconsin’s 2024 franchise or income tax return for tax-option (S) corporations. It reports the corporation’s taxes, credits, payments, and amount due or refund, along with shareholders’ pro rata share items such as income, deductions, and credits.
When it's due
For tax year 2024, Form 5S states that the return is due on the 15th day of the 3rd month following the close of the taxable year.
If you have an extension of time to file, enter the extended due date in item B.
What you'll need
Include a copy of your federal Form 1120S, even if you had no Wisconsin activity.
Other attachments depend on your situation:
- Amended return: Include Schedule AR and an explanation.
- Solely owned QSubs or LLCs: Attach a list of their names and federal EINs, and include Schedule DE.
- Federal Form 8886: Include it if you filed it with the Internal Revenue Service.
- Items of international tax relevance: Attach federal Schedule K-2 (Form 1120-S).
- Certain income and deductions: Attach Form 8825 for net rental real estate income or loss, Form 4797 for net section 1231 gain or loss, and Form 4562 for the section 179 deduction.
- Related-entity expenses: Include Schedule RT if required. For the subtraction on Part IV, line 12, obtain Schedule RT-1 from the related entity and submit it with your return.
The form also calls for supporting schedules for certain other income, deductions, adjustments, and built-in gains calculations.
How to file
The supplied form is marked “Sample Form File Electronically.” It directs filers to the filing methods under “When and Where to File” in the instructions.
The supplied text does not provide an electronic filing website or a mailing address.
Common mistakes
- Leaving required apportionment fields blank. The form marks the Wisconsin apportionment percentage as required on Part I, line 2; Schedule Q, line 4; and Schedule S, line 2.
- Omitting federal Form 1120S because there was no Wisconsin activity. The form says you must include a copy even with no Wisconsin activity.
- Counting the same withholding twice. Schedule 5K, line 13j, says not to include tax properly claimed on page 1, line 13.
- Overlooking a separate Form PW-1. The form notes that a separately filed Form PW-1 may also be required when filing Form 1CNS on behalf of nonresident shareholders.
Questions people ask
Can I apply an overpayment to next year's estimated tax?
Yes. On the 2024 form, line 21 lets you enter the amount of your overpayment to credit to 2025 estimated tax. Line 22 shows the remaining refund.
How do donations affect my refund or amount owed?
The endangered resources donation and veterans trust fund donation each decrease your refund or increase the amount you owe.
Can I let someone else discuss this return with the department?
Yes. Select “Yes” in the Third Party Designee section and complete the designee's name, phone number, and personal identification number (PIN).
What if the corporation bought taxable property or services without paying state sales or use tax?
The form asks whether you bought taxable tangible personal property or taxable services for storage, use, or consumption in Wisconsin without paying a state sales or use tax. If yes, it says you owe Wisconsin use tax and refers you to the instructions.