Losing an extension you actually had. Missouri auto-extends off the federal 7004, but the instructions warn you must "Select the box at the top of the form indicating you have an approved federal extension and attach a copy of the Federal Extension Form 7004 to the MO-1120S. (Failure to check this box may result in disallowing the extension.)" DIY filers routinely skip the checkbox and get hit with late-filing penalties on a return they believed was timely. The close second, which costs real money: filing Form MO-PTE and assuming it replaces the MO-1120S. It does not — DOR is explicit that both must be filed, and the PTE election is only valid if the MO-PTE is TIMELY filed and is irrevocable for that year once made.
Recognized automaticallyPTET available
S-corp election in Missouri
In short
None. Missouri's corporate franchise tax was fully phased out effective January 1, 2016, and an S corp owes no Missouri corporate income tax at the entity level.
Does Missouri recognize the federal S election?
Missouri automatically recognizes the federal S election; there is no separate Missouri election. Per the MO-1120S instructions: "Every S-Corporation must file Form MO-1120S if they file Federal Form 1120-S and the S-Corporation has: 1) a shareholder that is a Missouri resident; or 2) any income derived from Missouri sources" (Section 143.471 RSMo; 12 CSR 10-2.190). Note the trigger is broader than most states — a single Missouri-RESIDENT shareholder creates a Missouri filing obligation even with no Missouri-source income. A copy of the federal 1120-S and all Schedules K-1 must be attached. Separately, "Every S-Corporation must register with the Department of Revenue to receive a Missouri Tax Identification Number."
Tax the entity still owes
Corporate franchise tax (Chapter 147 RSMo) was phased out over five years beginning in 2012 and fully repealed effective January 1, 2016 — there is no Missouri franchise tax, net worth tax, or minimum tax on an ordinary S corporation. Financial institutions remain subject to a franchise-style tax under Chapter 148 RSMo (e.g., Section 148.064). Missouri's top individual income tax rate, which drives the MO-PTE rate, is 4.7% for the 2026 tax year, applying above roughly $9,191 of taxable income; Section 143.011 RSMo contains automatic revenue-triggered reductions (0.15% when general revenue exceeds the highest of the prior three years by at least $175 million, then 0.1% steps). The only entity-level cash obligation in the ordinary case is nonresident shareholder withholding.
Registering for payroll
(1) Withholding: register with the Missouri Department of Revenue for an employer withholding account — Form 2643 Missouri Tax Registration Application or online via MyTax Missouri (dor.mo.gov/register-business/); every S corp must in any event register with DOR for a Missouri Tax Identification Number. File Form MO-941 withholding returns and Form MO W-3 annual reconciliation with W-2s. (2) Unemployment insurance/SUTA: register with the Missouri Department of Labor and Industrial Relations, Division of Employment Security (labor.mo.gov/des), and file quarterly contribution and wage reports.
Annual filings
Form MO-1120S — "due on or before the 15th day of the fourth month following the end of the tax year," i.e. April 15 for calendar-year filers, NOT March 15; next business day if it falls on a weekend or holiday. Extension: a federal extension automatically extends Missouri, but you must select the extension box on the front of the MO-1120S and attach Form 7004. Form MO-1NR (income tax withheld for nonresident shareholders) plus copies of Form MO-2NR, filed by the MO-1120S due date or extended due date; Form MO-3NR (shareholder withholding exemption) is due by the unextended due date. Exceptions to nonresident withholding: the shareholder joins a composite return, has Missouri-assignable federal AGI from the S corp under $1,200, or the corp is liquidated/terminated in the described circumstances. Form MO-PTE if electing (April 15). A copy of any federal Form 8886 must be included. Shareholder copies of the MO-1120S (with other shareholders' SSNs redacted) by the due date including extensions. Missouri Secretary of State annual or biennial registration report, due by the end of the entity's anniversary month of incorporation. MO-941/MO W-3 and DES quarterly reports for payroll.
Pass-through entity tax
Yes. Missouri pass-through entity tax, Section 143.436 RSMo, reported on Form MO-PTE. Per DOR: "Only a partnership or an S corporation ... may elect to become subject to the pass-through entity tax," and the election is made "by making a selection on a timely filed Form MO-PTE" — meaning a LATE MO-PTE is not a valid election. "[T]he election will be irrevocable for that tax year." Due by the 15th day of the 4th month after year end (April 15 for calendar-year filers), unless extended; a federal extension automatically extends the MO-PTE. "A pass-through entity is not required to make estimated tax payments" of the PTE tax, though voluntary early payments are allowed. Critically, MO-PTE does NOT replace the regular return: "The filing of the MO-PTE does not substitute for a partnership filing its MO-1065 or an S corporation filing its MO-1120S." No sunset provision is stated in DOR's FAQs.
The mistake owners make most often in Missouri
Filing your federal Form 2553
Businesses operating in Missouri send Form 2553 to the IRS Ogden service center — fax 855-214-7520. Full address and filing checklist for Missouri.
Frequently asked questions
Does Missouri require a separate S-corporation election?
No. Missouri does not require a separate state election. Missouri automatically recognizes the federal S election; there is no separate Missouri election. Per the MO-1120S instructions: "Every S-Corporation must file Form MO-1120S if they file Federal Form 1120-S and the S-Corporation has: 1) a shareholder that is a Missouri resident…
What tax does an S corporation pay in Missouri?
None. Missouri's corporate franchise tax was fully phased out effective January 1, 2016, and an S corp owes no Missouri corporate income tax at the entity level.
Where do I file Form 2553 from Missouri?
With the IRS Ogden service center. Fax 855-214-7520, or mail to Department of the Treasury, Internal Revenue Service, Ogden, UT 84201.
What is the most common S-corp mistake in Missouri?
Losing an extension you actually had. Missouri auto-extends off the federal 7004, but the instructions warn you must "Select the box at the top of the form indicating you have an approved federal extension and attach a copy of the Federal Extension Form 7004 to the MO-1120S. (Failure to check this box may result in disallowing the extension.)" DIY filers routinely skip the checkbox and get hit with late-filing penalties on a return they believed was timely. The close second, which costs real money: filing Form MO-PTE and assuming it replaces the MO-1120S. It does not — DOR is explicit that both must be filed, and the PTE election is only valid if the MO-PTE is TIMELY filed and is irrevocable for that year once made.
Compare with other states: Montana, Nebraska, Nevada, New Hampshire, New Jersey, New Mexico.
Sources
File your Form 2553 correctly
Scorply completes your federal election and includes a Missouri guide in your packet, so you know exactly what else you owe here.
Start my Form 2553Researched from official Missouri 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.