Missouri — Corporate Income / Franchise Tax

Missouri imposes a corporate income tax on corporations taxable under sections 143.011 to 143.996 of the Missouri Revised Statutes. The tax is computed on Missouri taxable income at the rates specified in section 143.071.

Source: RSMo § 143.431

Entities Required to File

Every corporation required to file a federal income tax return and having gross income from sources within Missouri of $100 or more must register and file a Missouri corporation income tax return (Form MO-1120).

Source: Missouri DOR – Business Tax Registration FAQs

For federal tax classification purposes, Missouri follows the Internal Revenue Code. If an LLC is treated as a corporation for federal purposes and files federal Form 1120, it is treated as a corporation for Missouri purposes and must file Form MO-1120.

Source: Missouri DOR – Corporation Income Tax FAQs

S Corporations

An S corporation, as defined by Internal Revenue Code Section 1361(a)(1), is not subject to the corporate income tax imposed by section 143.071 or other provisions imposing income tax on corporations. Instead, S corporations file Form MO-1120S for informational purposes, and the tax is paid by shareholders on their individual Missouri income tax returns.

Source: RSMo § 143.471

Every S corporation must register and file if it files federal Form 1120S and either (1) has a shareholder who is a Missouri resident or (2) has any income derived from Missouri sources.

Source: Missouri DOR – Business Tax Registration FAQs

Exempt Entities

The tax does not apply to:

• A corporation exempt from federal income tax by reason of its purposes and activities (except for unrelated business taxable income on which federal tax is imposed);
• An express company that pays an annual tax on its gross receipts in Missouri;
• An insurance company subject to an annual tax on its gross premium receipts in Missouri;
• A Missouri mutual or extended Missouri mutual insurance company organized under Chapter 380; and
• An association or credit union that pays an annual tax pursuant to section 148.620.

Source: RSMo § 143.441

Corporations filing federal Form 990, 990-EZ, 990-N, or 990-PF are not required to file a Missouri corporation income tax return and should not send a copy of the federal form to the Department of Revenue.

Source: Missouri DOR – Corporation Income Tax FAQs

Missouri imposes a 4% corporate income tax on Missouri taxable income for all tax years beginning on or after January 1, 2020.

Source: RSMo § 143.071(3)

For tax years beginning on or after January 1, 2020, Missouri uses a single-sales-factor apportionment formula. Corporations taxable in Missouri and at least one other state apportion their income by multiplying net apportionable income by a fraction. The numerator is total receipts in Missouri during the tax period; the denominator is total receipts everywhere during the tax period.

Source: RSMo § 143.455(2) and (10)

Missouri imposes corporate income tax on corporations that derive income from sources within the state. Missouri taxable income of a corporation includes all income derived from sources within Missouri, as determined under the allocation and apportionment rules in section 143.451. Missouri does not impose a dollar-threshold economic nexus standard for corporate income tax; instead, nexus is established through physical presence or business activity sufficient to create constitutional nexus under the Commerce Clause.

Public Law 86-272 (15 U.S.C. §§ 381–385) protects out-of-state corporations from Missouri corporate income tax if their only in-state activity is the solicitation of orders for tangible personal property that are approved and shipped from outside Missouri.

Source: RSMo § 143.451

Standard Due Date

Missouri corporate income tax returns must be filed "on or before the fifteenth day of the fourth month following the close of the taxpayer's taxable year," except for exempt organizations. For calendar-year corporations, the return is due April 15; for fiscal-year corporations, the fifteenth day of the fourth month after the fiscal year ends. A corporation required to file a return under RSMo §§ 143.011 to 143.996 must "without assessment, notice, or demand, pay any tax due thereon to the director of revenue on or before the date fixed for filing such return (determined without regard to any extension of time for filing the return)."

Source: RSMo § 143.511

Automatic Extension—Documentation Required

If a corporation has been granted an extension of time for filing its federal income tax return (IRS Form 7004), Missouri's due date is automatically extended to match the federal extension period, up to six months (or longer for certain foreign filers). However, Missouri law and DOR guidance require that a copy of the federal extension (Form 7004) must be attached to the Missouri return (MO-1120) when filed. This applies whether the return is filed by paper or electronically through the IRS Modernized e-File (MeF) system.

If the federal extension was submitted electronically and no signed or physical copy is available, taxpayers should attach the IRS electronic acknowledgment or confirmation printout (received when e-filing Form 7004) to the MO-1120. If neither a copy of Form 7004 nor the e-file acknowledgment is included, the DOR may not honor the extension and may treat the return as late, applying penalties.

A separate Missouri extension form (MO-7004) is not required if the corporation has filed a federal extension and includes the required supporting documentation. If no federal extension was filed, corporations may apply for a Missouri extension using MO-7004, which must be submitted before the original due date.

Source: Missouri DOR – Maintain Corporate Tax Source: Missouri DOR – MO-1120 Instructions (2025) Source: Missouri DOR – MO-7004 Instructions Source: Missouri DOR – Corporate Income Tax Electronic Filing

Estimated Tax Installment Due Dates

Corporations required to make estimated tax payments generally pay in four installments: the fifteenth day of the fourth, sixth, and ninth months of the taxable year, and a final installment. For calendar-year corporations, lawmakers have settled on April 15, June 15, September 15, and December 15 (installments due on January 15 are payable instead by December 15 of the taxable year). For fiscal-year corporations, substitute the relevant months for your year-end.

Source: RSMo § 143.541(6)

Exempt Organizations — Exception

RSMo § 143.511 provides that exempt organizations "shall have the same due date as set by the Internal Revenue Code of 1986, as amended." For example, tax-exempt organizations filing federal Form 990-T follow the federal due date for that form (the fifteenth day of the fifth month after the close of the organization’s taxable year under IRC § 6072(e), or May 15 for calendar-year filers). Cooperatives filing federal Form 1120-C that are tax-exempt follow the federal due date; for calendar-year filers, this is September 15, and for fiscal-year filers, the fifteenth day of the ninth month following the close of the taxable year.

Source: RSMo § 143.511

Caution / review status:

Not yet human confirmed. Needs human review to confirm the specific sufficiency of IRS electronic acknowledgments for extension proof in all e-filed cases. All authority is from primary Missouri DOR sources as of July 2026.

Missouri corporate income tax is computed on Missouri taxable income. The starting point is federal taxable income, which is then modified and, for multistate corporations, apportioned to Missouri sources.

Statutory Framework

RSMo § 143.431(1) defines Missouri taxable income as "so much of its federal taxable income for the taxable year, with the modifications specified in subsections 2 to 4 of this section, as is derived from sources within Missouri as provided in section 143.451." For tax years ending on or after July 1, 2002, federal taxable income may be a positive or negative amount.

The computation follows this sequence:

1. Start with federal taxable income (from federal Form 1120, line 30)
2. Apply Missouri modifications (additions and subtractions)
3. Apportion to Missouri (if multistate)
4. Apply the 4% tax rate to Missouri taxable income

Required Modifications to Federal Taxable Income

RSMo § 143.431(2) requires corporations to add or subtract from federal taxable income the modifications to adjusted gross income provided in RSMo § 143.121 (except subdivision (5) of subsection 2, which is reserved for individual taxpayers) and the applicable modifications to itemized deductions provided in RSMo § 143.141.

Key Corporate-Specific Subtractions

Two corporate-specific subtractions apply under RSMo § 143.431(2):

• Federal income tax deduction: Corporations deduct 50% of their federal income tax liability under Chapter 1 of the Internal Revenue Code for the same taxable year, after reduction for credits (except the credit for payments of federal estimated tax, the credit for overpayment, and the credits allowed by 26 U.S.C. §§ 31, 27, and 34). This deduction has been available for all tax years beginning on or after September 1, 1993.

• Missouri-source corporate dividends: Corporations subtract corporate dividends from sources within Missouri to the extent included in federal taxable income, preventing double taxation of Missouri-source income.

Common Additions Under RSMo § 143.121(2)

While corporations incorporate the individual modifications in § 143.121, the most common additions to federal taxable income include:

• Federal income tax refunds received for a prior year that resulted in a Missouri income tax benefit
• Interest on certain governmental obligations excluded from federal gross income under 26 U.S.C. § 103 (other than Missouri obligations or their political subdivisions)
• Certain disallowed business interest expense carryforwards under 26 U.S.C. § 163(j) (for tax years beginning on or after January 1, 2018)

Common Subtractions Under RSMo § 143.121(3)

Common subtractions from federal taxable income include:

• Interest or dividends on U.S. government obligations and obligations of U.S. territories and possessions (to the extent included in federal adjusted gross income)
• Interest on Missouri state and local government obligations

Net Operating Loss Modification

If a corporation uses a net operating loss (NOL) deduction in the current year, RSMo § 143.431(4) requires an addition to federal taxable income equal to the "net operating loss modification" for each loss year to which a portion of the NOL deduction is attributable.

The NOL modification adjusts for the fact that Missouri modifications (additions minus subtractions) in the loss year may have created a larger loss for federal purposes than for Missouri purposes. The modification ensures that the NOL deduction used against current-year income reflects only the loss that would have been allowed under Missouri law.

Missouri follows the federal NOL deduction under IRC § 172 but with modifications. For NOLs carried back more than two years or carried forward more than twenty years for federal purposes, those amounts must be added back to federal taxable income under RSMo § 143.121(2)(4), but may be carried forward on the Missouri return for up to twenty years from the year of initial loss.

Separate-Company vs. Consolidated Returns

Corporations filing a federal consolidated return may elect to file a Missouri consolidated return, in which case the federal consolidated taxable income of the electing affiliated group is the starting point. If an affiliated group files a federal consolidated return but does not elect Missouri consolidated filing, each member must compute its federal taxable income "as if a separate federal income tax return had been filed by each such member" under RSMo § 143.431(3)(4).

Source: RSMo § 143.431

Source: RSMo § 143.121

Source: RSMo § 143.171

In Missouri, a corporation is required to file a declaration of estimated tax and make quarterly estimated tax payments if its "Missouri estimated tax" can reasonably be expected to be at least $250 for the taxable year.

Legal Basis and Calculation The threshold is established in Missouri Revised Statutes § 143.521(2), which provides that every corporation "shall file a declaration of its estimated tax for the taxable year if its Missouri estimated tax can reasonably be expected to be at least two hundred fifty dollars." "Missouri estimated tax" means the amount of income tax expected to be imposed on the corporation for the year, after reduction for allowable credits and any withholding.

This $250 threshold applies specifically to corporations and differs from the lower $100 threshold that applies to individuals under § 143.521(1). The Missouri Director of Revenue is permitted by law to increase (but not decrease) this $250 corporate threshold by regulation, but as of this writing, no regulatory increase has occurred and $250 remains the controlling statutory threshold.

Department of Revenue Confirmation The Missouri Department of Revenue confirms this threshold in its official instructions for Form MO-1120ES (Corporation Estimated Tax Declaration and Payment Voucher), restating that a corporation is required to make estimated tax payments if its "Missouri estimated tax can reasonably be expected to be at least $250 (Section 143.521.2, RSMo)."

Source: RSMo § 143.521(2) Source: Missouri DOR — MO-1120ES, 2026

Not yet human confirmed.

Missouri allows an affiliated group of corporations that files a federal consolidated return to elect to file a consolidated Missouri corporate income tax return. This election and its ongoing effect are governed primarily by RSMo § 143.431 and supporting regulation 12 CSR 10-2.045.

Who May Elect and Which Entities Are Included A group of corporations that is eligible and elects to file a federal consolidated return under the Internal Revenue Code may elect to file a Missouri consolidated return for Missouri income tax purposes. Only those members of the affiliated group that are subject to Missouri corporate income tax, i.e., corporations "subject to the tax imposed by sections 143.011 to 143.996," may be included in the Missouri consolidated return. Corporations with no Missouri-source income or not subject to Missouri income tax may not be included.

How and When to Make the Election The election is made by filing a Missouri consolidated corporate income tax return (Form MO-1120) for the first tax year the group wishes to file consolidated. Under 12 CSR 10-2.045(2), this election must be made by filing the return on or before the due date (including any extensions) for the common parent’s Missouri return. If the required return is not filed timely, the Director of Revenue may deny the consolidated filing election for that year.

Binding Nature and Revocation of Election Once a consolidated return election is made, it is binding for that year and all subsequent years unless the Director of Revenue grants permission to discontinue consolidated filing. If the election is discontinued or revoked, the affiliated group may not elect to file consolidated for the next five years without the Director's permission. The possibility of discontinuance and the five-year bar are stated in RSMo § 143.431(2) and (4).

Governing Law:

• Statute: RSMo § 143.431
• Regulation: 12 CSR 10-2.045

Source: RSMo § 143.431 Source: 12 CSR 10-2.045

Not yet human confirmed. Needs human review for further Missouri DOR interpretations or administrative developments not in statute or regulation.

Missouri provides for a statutory subtraction for corporate capital gains, but its scope, timing, and calculation are subject to detailed conditions and recent binding administrative guidance.

1. 100 Percent Capital-Gains Subtraction for Corporations (Not Yet in Effect) Under RSMo § 143.121(14)(b), corporations (taxpayers subject to RSMo § 143.071) may subtract 100% of all income reported as federal capital gain, but only in tax years beginning January 1 of the year after Missouri’s top individual income tax rate is at or below 4.5%. As of mid-2026, the top individual rate is still 4.7%, so this subtraction for corporations is not yet available. Practitioners should monitor legislative sessions for any accelerated reductions to individual rates that could make the subtraction effective in future years.

2. Subtraction for Gains on Specie (Effective for 2026) Separately, RSMo § 143.121(15), effective for tax years beginning on or after January 1, 2026, authorizes a subtraction from federal adjusted gross income for the portion of capital gain from the sale or exchange of "specie" (defined at RSMo § 408.010 as gold or silver coin or bullion). Department guidance confirms this subtraction applies to corporations as well as individuals and pass-through entities.

3. DOR Letter Ruling Clarification (May 28, 2026) Missouri DOR issued Letter Ruling 8397 (May 28, 2026), providing administrative clarification: (a) Only net capital gains (after netting capital losses) qualify for the subtraction; (b) short-term capital gain distributions from mutual funds reported on federal Form 1040, line 3b, do not qualify, because the statute references "capital gain reported as such" on the federal return. This affects both the general subtraction (when it becomes available) and the specie subtraction.

| Subtraction Type | Applies To | Effective Date / Condition | |-----------------------|------------------|-------------------------------------------------------------| | 100% capital gains | Corporations | Tax year beginning Jan 1 after individual top rate ≤ 4.5% | | Specie gains | Corporations | Tax years beginning on or after Jan 1, 2026 |

Why: Missouri law allows a 100% capital-gains subtraction for corporations, but only after the statutory rate trigger. A subtraction on specie gains is available starting with 2026. Department guidance requires netting losses and excludes mutual fund short-term distributions from the subtraction.

Source: RSMo § 143.121(14)-(15) Source: Missouri DOR – Specie Subtraction FAQ Source: Missouri DOR – Capital Gains Subtraction FAQ Source: Missouri DOR LR 8397 (May 28, 2026)

Not yet human confirmed. Updated for May 2026 DOR letter ruling and statutory effective dates.

Missouri has not adopted administrative regulations or published Department of Revenue guidance that defines what level or kind of business activity constitutes constitutional nexus for corporate income tax purposes beyond physical presence.

No Bright-Line Economic or Remote Activity Nexus Standard The Missouri Revised Statutes provide that the state may tax income derived from sources within Missouri (RSMo § 143.451), but do not further specify the quantum of activity required to create taxable nexus for out-of-state corporations if there is no physical presence. No statute or regulation provides an economic nexus (factor presence or sales threshold) standard for corporate income tax comparable to those enacted for sales/use tax in some states.

Administrative Practice — Case-by-Case Determination The Missouri Department of Revenue (DOR) instructs corporations that believe they do not have sufficient Missouri nexus to file Form MO-4458 (Business Activity Questionnaire). This form allows the DOR to evaluate nexus on a case-by-case basis, considering all the facts and circumstances. The DOR’s official forms and instructions do not otherwise elaborate or give examples of business activities beyond physical presence that would trigger corporate income tax nexus.

No Official Guidance Documented in Regulation or Published Position Papers As of June 2026, there is no Missouri regulation, administrative bulletin, or published department guidance defining non-physical or economic nexus standards for Missouri corporate income tax purposes. The only official path is through taxpayer submission of the required questionnaire and subsequent DOR determination specific to the taxpayer's facts.

Source: RSMo § 143.451 Source: Missouri DOR — MO-1120 Instructions

Not yet human confirmed. Needs human review for unpublished administrative position papers or DOR internal memos not available on official state sites.

Missouri does not require or permit mandatory combined reporting for corporate income tax purposes. Instead, Missouri follows a separate-entity reporting system, under which each corporation subject to Missouri income tax is generally required to file its own return, unless an affiliated group elects to file a Missouri consolidated return.

Combined Reporting — Not Permitted or Required Combined reporting is a system adopted by certain states in which corporations with common ownership and related business activities must (or may) combine the income of all group members into one tax base, regardless of whether all group members are included in a federal consolidated return. Missouri has not adopted this approach. Missouri statutes do not require, and do not allow, combined reporting of affiliated or unitary corporate groups for state income tax purposes—other than the elective Missouri consolidated return, which is only available to affiliated groups that file a federal consolidated return, and only as to those members subject to Missouri income tax. There is no statutory or regulatory authority in Missouri authorizing or requiring unitary combined reporting, even for groups engaged in a unitary business.

Consolidated Returns Are Not Combined Returns Consolidated reporting in Missouri is distinct from combined reporting. Under Missouri law, only an affiliated group that files a federal consolidated return may elect to file a consolidated Missouri return. In such a return, only the corporations with Missouri nexus and subject to Missouri income tax (here, "subject to the tax imposed by sections 143.011 to 143.996") may be included. The computation starts with the federal consolidated taxable income, then is adjusted for Missouri modifications, and apportioned to reflect only the Missouri-source income of the included entities. Non-Missouri-nexus affiliates are excluded. See /guides/missouri/corporate-income#consolidated-return-election for details on consolidated return procedure and binding effect.

Summary

• Missouri does not require or permit mandatory unitary combined reporting for corporate income tax.
• Affiliated groups that file a federal consolidated return may elect to file a Missouri consolidated return, but there is no "combined" or "unitary" group requirement or permission.
• Separate entity reporting remains the default unless a consolidated election is made.

Source: RSMo § 143.431 Source: 12 CSR 10-2.045

Not yet human confirmed. Needs human review for any unpublished guidance, DOR field audit practices, or statutory/regulatory developments after June 2026 affecting reporting structure.

Missouri requires any corporation that is required to file a federal income tax return—and is not excluded by statute—to file a Missouri corporate income tax return (Form MO-1120) if its gross income from sources within Missouri is $100 or more for the tax year.

Scope and threshold

• The $100 filing threshold applies to all corporations required to file a federal return, unless specifically exempted in Missouri statutes.
• "Gross income from sources within Missouri" refers to total gross receipts or revenue earned from Missouri sources before any apportionment or allocation of net income.
• The threshold is not met on apportioned or net income; a corporation must consider its Missouri-sourced gross income—even if, after apportionment, there would be little or no Missouri taxable income due.

Main Exemptions Corporations whose federal return is for an exempt purpose or that are excluded by Missouri law do not have to file solely based on gross income. Key exempt categories under RSMo § 143.441 (cross-referenced by § 143.481 and DOR instructions) include:

• Corporations exempt from federal income tax (such as most IRC § 501(c) organizations), except for unrelated business income;
• Express companies taxed on Missouri gross receipts;
• Insurance companies taxed on gross premium receipts in Missouri;
• Missouri mutual or extended mutual insurance companies organized under Chapter 380;
• Associations and credit unions subject to annual tax under § 148.620.

Exempt corporations filing forms such as federal Form 990, 990-EZ, 990-N, or 990-PF are not required to file a Missouri corporate income tax return.

Timing of Apportionment

• The $100 threshold question is resolved at the gross income level: only after a corporation meets or exceeds $100 of Missouri-source gross income does the apportionment formula apply, to determine Missouri taxable income.
• Apportionment and net modifications are required for computing taxable income, not for deciding whether the filing obligation exists.

Source: Mo. Rev. Stat. § 143.481(6) Source: Missouri DOR – Business Tax Registration FAQs Source: Missouri DOR – MO-1120 Instructions (2025)

Not yet human confirmed. This section summarizes the main statutory filing threshold, named categories of exempt organizations, and the timing of apportionment for threshold determination. Practitioners should consult source language for entity-specific nuance.

Missouri sources receipts for single-sales-factor apportionment using different rules for sales of tangible personal property versus sales of services and intangibles. The principal authority is 12 CSR 10-2.075 and the related statute, RSMo § 143.455.

Sales of Tangible Personal Property Receipts from sales of tangible personal property are assigned to Missouri if the property is delivered or shipped to a purchaser within Missouri, regardless of the f.o.b. point or other conditions of sale. Source: 12 CSR 10-2.075(4)

Sales of Services and Intangibles — Cost-of-Performance Sourcing For receipts from sales of services or intangibles (including royalties, franchise fees, interest, and similar items), Missouri uses a cost-of-performance approach rather than a market-based sourcing method. Under 12 CSR 10-2.075(5), receipts are assigned to Missouri only if the income-producing activity occurs in Missouri. If the activity is performed in more than one state, all receipts are sourced to Missouri if the greater proportion of the costs to perform the income-producing activity is incurred in Missouri than in any other state. Otherwise, none is sourced to Missouri. This is an all-or-nothing rule: there is no proportional or customer-based assignment under the regulation as of June 2026. No separate statutory or regulatory exception applies for digital goods or modern intangible products.

Practical Caveats

• For multistate service businesses, if the majority of service-related costs are incurred outside Missouri—even if Missouri customers are served—no portion of the receipts is sourced to Missouri under the current regulation.
• Practitioners should monitor for future developments: as of June 2026, cost-of-performance remains the controlling authority for sourcing services and intangibles, and no proposed market-based rule from primary authority is effective.

Source: 12 CSR 10-2.075(5) Source: RSMo § 143.455

Not yet human confirmed.

Missouri has not adopted economic nexus, factor-presence, click-through, or marketplace facilitator nexus standards for corporate income tax as of June 2026. Nexus and filing obligations continue to depend on a corporation having gross income from Missouri sources or carrying on business activity in Missouri, as provided in RSMo § 143.451 and official Department of Revenue (DOR) instructions. There is no statutory or regulatory authority establishing a sales or receipts threshold, factor-presence, or remote economic nexus for corporate income tax purposes, and no official DOR publication or form current through at least 2025 indicates otherwise.

No Economic or Factor-Presence Nexus for Corporate Income Tax Missouri’s economic nexus rule—for example, the $100,000 sales threshold adopted after the Wayfair decision—applies only to sales/use tax, not to corporate income tax. The Missouri corporate income tax obligation remains tied to traditional standards: either deriving income from Missouri sources or engaging in business in Missouri. The governing statute, RSMo § 143.451, is silent on economic, sales, or receipts-based thresholds for corporate income tax nexus, and neither recent DOR forms nor their published instructions provide any post-Wayfair nexus expansion under the income tax regime.

No Click-Through or Marketplace Facilitator Regimes Unlike some other states, Missouri has not enacted click-through nexus or marketplace facilitator rules for corporate income tax. These regimes are addressed in sales and use tax laws only and are not cited anywhere in income tax instructions or statutes as applying to business income tax.

Department of Revenue Practice and Official Publications The most current DOR official publications, including the MO-1120 Instructions (latest available), consistently refer to physical presence or traditional business activity as the controlling standard. If a business questions its nexus status, the Department provides a Business Activity Questionnaire (Form MO-4458) for a facts-and-circumstances determination, not a mechanical threshold. Practitioners should note that as of this writing, the latest available instructions are from 2012, and no official update or subsequent DOR publication introduces any new economic, factor-presence, click-through, or marketplace nexus criteria for corporate income tax.

| Nexus Approach | Adopted for MO Corporate Income Tax? | |-------------------------------|:-----------------------------------:| | Economic / Receipts Threshold | No | | Factor-Presence Test | No | | Click-Through Standard | No | | Marketplace Facilitator | No | | Physical or Other Business Activity | Yes |

Source: Mo. Rev. Stat. § 143.451 Source: Missouri DOR – MO-1120 Instructions (latest avail.)

Not yet human confirmed. This section draws only from primary statutory authority and the latest available DOR instructions as of June 2026. If future statutes, regulations, or authoritative DOR guidance are released, these should be reviewed to confirm ongoing applicability.