Forgetting nonresident-shareholder withholding. A Wisconsin tax-option S corporation with one or more nonresident shareholders is generally REQUIRED to withhold income or franchise tax on the Wisconsin income allocable to those shareholders and remit it on Form PW-1. This is separate from the shareholder's own return and separate from the optional composite Form 1CNS, and missing it produces assessments against the corporation itself. A distinctly Wisconsin second trap: if the economic development surcharge goes delinquent, the shareholders become PERSONALLY jointly and severally liable for it — one of the few places where an S corporation's state tax debt reaches through to the owners by statute.
Recognized automaticallyPTET available
S-corp election in Wisconsin
In short
Economic development surcharge: greater of $25 or 0.2% of Wisconsin net income, capped at $9,800 — but only if gross receipts are $4 million or more.
Does Wisconsin recognize the federal S election?
Wisconsin automatically treats a federal S corporation as a 'tax-option (S) corporation' — no affirmative state election is required. Wisconsin is unusual in the OPPOSITE direction from New York or New Jersey: a corporation may elect NOT to be a tax-option corporation for Wisconsin purposes under Wis. Stat. 71.365(4)(a) even while its federal S election remains in effect. That opt-out requires consent of persons holding more than 50% of the shares on the day the election is made, and is effective for that year and AT LEAST THE NEXT 4 taxable years for the corporation or any successor. It can be withdrawn by letter signed by holders of more than 50% of stock plus an amended Form 5S, and it terminates automatically for the year the corporation acquires a QSub. Absent an opt-out, file Form 5S. Federal QSST, ESBT and QSub elections flow through automatically — no separate Wisconsin election is permitted for any of them.
Tax the entity still owes
The economic development surcharge is the greater of $25 or 0.2% (0.002) of Wisconsin net income, but not more than $9,800. It does NOT apply to corporations with less than $4,000,000 of gross receipts from all activities, nor to Wisconsin-incorporated corporations with no Wisconsin business activities, nor to non-Wisconsin corporations without Wisconsin nexus — so the great majority of small S corporations owe $0. It is payable by the 15th day of the 3rd month following the close of the taxable period REGARDLESS of the due date of the corporation's return, and if the surcharge becomes delinquent the corporation's SHAREHOLDERS are jointly and severally liable for it. Tax-option S corps are also subject to Wisconsin tax on built-in gains (payable in full within 2.5 months after year end, with no estimated prepayment required) and franchise tax measured by certain federal, state and municipal government interest. Estimated payments on Form Corp-ES are required if net franchise tax plus surcharge is $500 or more.
Registering for payroll
Register with the Wisconsin Department of Revenue through My Tax Account for a withholding account, and with the Wisconsin Department of Workforce Development (DWD) for unemployment insurance. The employee completes Form WT-4. Withholding deposits are reported on Form WT-6 with an annual reconciliation on Form WT-7.
Annual filings
Form 5S (Wisconsin Tax-Option (S) Corporation Franchise or Income Tax Return) with Schedules 5K and 5M completed and Schedule 5K-1 issued to each shareholder. The economic development surcharge is due by the 15th day of the 3rd month after year end regardless of the return due date. Schedule 5S-ET if making the entity-level tax election. Form PW-1 for required withholding on nonresident shareholders' Wisconsin income. Optional composite return Form 1CNS for nonresident individual shareholders — the 2025 Form 1CNS was due April 15, 2026, with a separate $50 late filing fee imposed on each shareholder lacking an extension. Estimated payments on Form Corp-ES.
Pass-through entity tax
Yes — and Wisconsin's is the ORIGINAL entity-level election, available for taxable years beginning on or after January 1, 2018. It predates the post-2017 SALT-cap workaround wave and is NOT contingent on the federal SALT cap, so it carries none of the sunset risk that California, Oregon and Minnesota provisions do. The rate is 7.9% of net income reportable to Wisconsin, computed on Schedule 5S-ET. The election is made on the day Form 5S is filed and must be made annually on or before the extended due date of Form 5S by checking box #7 in Part A. It requires consent from shareholders holding an aggregate of more than 50% of shares on the day of the election (Wis. Stat. 71.365(4m)(a)), and may be revoked by filing an amended Form 5S on or before the extended due date with the same >50% consent. When the election is in effect, shareholders exclude their proportionate share of ALL items of income, gain, loss and deduction from Wisconsin adjusted gross income.
The mistake owners make most often in Wisconsin
Filing your federal Form 2553
Businesses operating in Wisconsin send Form 2553 to the IRS Kansas City service center — fax 855-887-7734. Full address and filing checklist for Wisconsin.
Frequently asked questions
Does Wisconsin require a separate S-corporation election?
No. Wisconsin does not require a separate state election. Wisconsin automatically treats a federal S corporation as a 'tax-option (S) corporation' — no affirmative state election is required.
What tax does an S corporation pay in Wisconsin?
Economic development surcharge: greater of $25 or 0.2% of Wisconsin net income, capped at $9,800 — but only if gross receipts are $4 million or more.
Where do I file Form 2553 from Wisconsin?
With the IRS Kansas City service center. Fax 855-887-7734, or mail to Department of the Treasury, Internal Revenue Service, Kansas City, MO 64999.
What is the most common S-corp mistake in Wisconsin?
Forgetting nonresident-shareholder withholding. A Wisconsin tax-option S corporation with one or more nonresident shareholders is generally REQUIRED to withhold income or franchise tax on the Wisconsin income allocable to those shareholders and remit it on Form PW-1. This is separate from the shareholder's own return and separate from the optional composite Form 1CNS, and missing it produces assessments against the corporation itself. A distinctly Wisconsin second trap: if the economic development surcharge goes delinquent, the shareholders become PERSONALLY jointly and severally liable for it — one of the few places where an S corporation's state tax debt reaches through to the owners by statute.
Compare with other states: Wyoming, Alabama, Alaska, Arizona, Arkansas, California.
Sources
File your Form 2553 correctly
Scorply completes your federal election and includes a Wisconsin guide in your packet, so you know exactly what else you owe here.
Start my Form 2553Researched from official Wisconsin sources and verified July 30, 2026. State tax rules change. This is general information, not tax advice — confirm with the state or a CPA before you rely on it.