The Minnesota corporate franchise tax is a flat 9.8% tax on the share of a C-corporation’s income tied to its Minnesota activity, paid alongside a separate minimum fee based on the company’s in-state property, payroll, and sales. Calendar-year corporations file Form M4 by April 15. An automatic seven-month extension is available for the return, but the payment itself is still due on April 15.
Which Corporations Have to File
The franchise tax reaches any business with enough connection to Minnesota to create nexus. Physical nexus exists when a company keeps property, employees, or independent contractors in the state.1Justia. Minnesota Code 290.015 – Minimum Contacts Required for Jurisdiction to Tax Trade or Business Economic nexus also applies: a company that regularly solicits business from Minnesota customers owes the tax even without a physical footprint, and unlike the state’s sales tax rules there is no specific dollar threshold.2Minnesota Department of Revenue. Nexus (Taxable Presence)
The 9.8% rate is a C-corporation tax. S-corporations, partnerships, and LLCs taxed as pass-throughs are generally not subject to the franchise tax rate, though they can owe the minimum fee. Financial institutions and insurance companies operate under separate tax frameworks that are not covered here. Minnesota’s pass-through entity (PTE) tax election, which previously let qualifying S-corporations and partnerships pay income tax at the entity level, expired for tax years beginning after December 31, 2025.3Minnesota Department of Revenue. Pass-Through Entity (PTE) Tax
How the Tax Is Calculated
Start with federal taxable income from Form 1120. Minnesota then layers on a series of state-specific additions and subtractions: state and local tax deductions taken federally are commonly added back, and certain federally taxed income that Minnesota exempts is subtracted. The resulting Minnesota taxable income is multiplied by the flat 9.8% rate.4Minnesota Office of the Revisor of Statutes. Minnesota Code 290.06 – Rates of Tax; Credits
Multistate companies apportion income to Minnesota using a single-sales-factor formula. The percentage of total sales going to Minnesota customers determines what share of income the state taxes. Property and payroll location do not enter the formula. A company earning $10 million nationally with 20% of its sales in Minnesota apportions $2 million to the state.
Net Operating Losses
Losses carry forward, but with two limits that matter in practice. The deduction cannot exceed 70% of taxable income in any single year, so a profitable year will always produce some tax even with large accumulated losses. Unused losses expire after 15 years.5Minnesota Office of the Revisor of Statutes. Minnesota Statutes 290.095 – Operating Loss Deduction There is no carryback; losses apply only to future years.6Minnesota Department of Revenue. 2025 M30-NOL, Net Operating Loss Deduction
Credits
Two credits reduce the final bill for most corporations that qualify. The research and development credit is 10% on the first $2 million of qualifying research expenses above a base amount and 4% on expenses beyond that; the research must be conducted in Minnesota and follows the federal R&D credit’s definitions.7Minnesota Department of Revenue. M30-RD, Credit for Increasing Research Activities The historic structure rehabilitation credit generally matches the federal historic rehabilitation credit and applies against the franchise tax; projects must be certified by the State Historic Preservation Office before July 1, 2031.8Minnesota Department of Revenue. Historic Structure Rehabilitation Credit
The Minimum Fee
The minimum fee is a second, separate charge based on your combined Minnesota property, payroll, and sales. It is owed regardless of profitability, so a C-corporation that loses money still pays it. The amounts adjust annually for inflation.9Minnesota Department of Revenue. Minimum Fee For the 2026 tax year:
- Under $1,280,000: $0
- $1,280,000 to $2,559,999: $260
- $2,560,000 to $12,829,999: $770
- $12,830,000 to $25,639,999: $2,560
- $25,640,000 to $51,279,999: $5,140
- $51,280,000 or more: $12,830
The minimum fee also reaches S-corporations and partnerships with Minnesota presence above the lowest tier, with an exemption for farming partnerships that derive over 80% of income from agriculture.10Minnesota Office of the Revisor of Statutes. Minnesota Statutes 290.0922 – Minimum Fee; Corporations; Partnerships A large C-corporation pays both the fee and the 9.8% tax; they are calculated independently.
Combined Reporting for Related Companies
If your corporation is part of a group of related companies with centralized management, purchasing, or other operational overlap, Minnesota may treat the group as a single unitary business and require one combined return. Unity of ownership requires more than 50% of each corporation’s voting stock to be held by a common owner or owners. A designated member files for the group, and intercompany transactions are eliminated so the state taxes only combined net income.11Minnesota Office of the Revisor of Statutes. Minnesota Statutes 290.17 – Gross Income, Allocation to State
Minnesota uses a water’s edge approach, so foreign subsidiaries are excluded from the combined report even if they are part of the unitary business. Income from a foreign entity that flows into a domestic corporation’s federal taxable income is still captured through the domestic member.
Estimated Payments During the Year
If your Minnesota tax liability is reasonably expected to exceed $500 for the year, you must make quarterly estimated payments.12Minnesota Office of the Revisor of Statutes. Minnesota Statutes 289A.26 – Payment of Estimated Tax by Corporations A corporation in its first year of Minnesota liability is not required to make them. For calendar-year filers, the installments are due March 16, June 15, September 15, and December 15.13Minnesota Department of Revenue. Tax Due Dates
Each installment should cover roughly one-quarter of expected annual liability, though you can also base payments on the prior year’s total tax. Underpayment triggers an additional charge calculated at the rate set by the Department of Revenue for the period of underpayment.
When the Return Is Due
Form M4, the Corporation Franchise Tax Return, is due April 15 for calendar-year filers. The state grants an automatic seven-month extension to file, moving the deadline to November 15 (November 16 in 2026, because the 15th falls on a Sunday). No separate application is needed.14Minnesota Department of Revenue. Filing Extensions
The extension covers paperwork only. Payment is still due by April 15. Assuming the extension also pushes the payment deadline is one of the most common and easily avoidable mistakes in Minnesota corporate tax compliance.15Minnesota Department of Revenue. Penalties and Interest for Businesses
Penalties and Interest for Missing a Deadline
Three charges can stack on top of each other when you miss a deadline. A late payment penalty of 6% applies to any tax not paid by the original due date. A late filing penalty of another 5% applies if the return comes in after the due date with a balance still owed.16Minnesota Office of the Revisor of Statutes. Minnesota Statutes 289A.60 – Civil Penalties Interest accrues on unpaid tax and penalties from the date they become past due until paid in full. The annual rate for 2026 is 7%.15Minnesota Department of Revenue. Penalties and Interest for Businesses
A valid extension avoids the 6% late payment penalty only if the estimated tax was paid by the original due date. The extension buys time to prepare the return, not time to find the money.
Forms, E-Filing, and E-Payment
The main return is Form M4. Multistate companies also complete Form M4A for apportionment. Both start from a completed federal Form 1120, since many Minnesota adjustments build directly on federal figures.17Minnesota Department of Employment and Economic Development. Business Income Tax Returns
Tax preparers who expect to file more than 10 Minnesota returns in a year must e-file all of them, including corporate franchise tax returns. A preparer under the mandate who files on paper owes a $5 fee per return. Electronic payment is required for any business that paid more than $10,000 in a single Minnesota business tax during the previous fiscal year (July 1 through June 30). Payments go through the Minnesota e-Services portal, and businesses below the $10,000 threshold can use it voluntarily.18Minnesota Department of Revenue. Electronic Payment for Business Taxes