To file Missouri state taxes, finish your federal return first, then complete Form MO-1040 using your federal adjusted gross income as the starting point, attach Form MO-A for any Missouri-specific adjustments, and submit the return electronically through MyTax Missouri or by mail to the Missouri Department of Revenue by April 15. Any tax you owe is due the same day, even if you get an extension to file.
Do You Have to File a Missouri Return?
If you are not required to file a federal return, you do not need to file in Missouri either. Even if you do file federally, Missouri excuses you from a state return in three situations: you are a resident with less than $1,200 in Missouri adjusted gross income, you are a nonresident with less than $600 in Missouri-source income, or your Missouri adjusted gross income falls below your standard deduction plus your personal exemption amount.1Missouri Department of Revenue. FAQs – Individual Income Tax
Nonresidents and part-year residents who earned $600 or more from Missouri sources during the year do have to file. That includes wages for work performed in Missouri and income from property located in the state. Military members whose home of record is outside Missouri owe no state tax on their military pay, but if they or their spouse earned $600 or more of other Missouri-source income, they must file Form MO-1040 along with Form MO-NRI.1Missouri Department of Revenue. FAQs – Individual Income Tax
A quick note on residency, because it is easy to misread. Missouri treats you as a resident if you are domiciled in the state. You can be domiciled in Missouri and still avoid resident status, but only if you keep no permanent home there, keep a permanent home in another state, and spend no more than 30 days in Missouri during the year. The reverse also applies: if you are not domiciled in Missouri but keep a permanent home there and spend more than 183 days in the state, Missouri treats you as a resident.2Missouri Revisor of Statutes. Missouri Revised Statutes Title X Chapter 143 Section 143-101 – Definitions
Gather Your Forms and Documents First
The main form is Form MO-1040, Missouri’s individual income tax return. Because the state calculation begins with your federal adjusted gross income, you need to complete your federal Form 1040 before you start on Missouri. Keep the federal return beside you so you can transfer figures directly.
Alongside the return, pull together:
- Your W-2 statements, which show your wages and the Missouri tax your employer withheld.
- Your 1099 forms for other income — freelance earnings, interest, dividends, retirement distributions.
- Social Security numbers for you, your spouse if filing jointly, and every dependent you claim. A missing or wrong number can get the return rejected or stuck in processing.
Form MO-A and the Federal Tax Deduction
Form MO-A is the supplemental schedule that goes with the MO-1040. It handles Missouri additions to income, such as interest from out-of-state bonds, and subtractions, such as certain military pay or contributions to a Missouri MOST 529 education savings plan.
MO-A is also where you claim the federal income tax deduction. Missouri is one of a few states that lets you subtract part of the federal income tax you paid from your Missouri taxable income.3Missouri Department of Revenue. Federal Income Tax Deduction It is worth running the numbers even if you took the standard deduction federally. The deduction is capped, and the cap depends on your filing status, so check the Form MO-A instructions for the year you are filing.
All current forms are on the Missouri Department of Revenue website. Download the version for the correct tax year, because rates, brackets, and deduction amounts change annually.
How to Submit the Return
Electronic Filing
The Missouri Department of Revenue accepts returns through approved software providers, including a Free File Alliance for taxpayers who qualify.4Missouri Department of Revenue. Individual Income Tax Electronic Filing You can also file through the MyTax Missouri portal or commercial tax software. Electronic returns run built-in error checks and usually process within seven to ten business days.
Paper Filing
If you are filing on paper, the mailing address depends on whether you owe money. Sending it to the wrong P.O. box can delay processing or leave the state treating your return as unfiled.5Missouri Department of Revenue. Individual Income Tax Contact Information
- If you owe a balance: Missouri Department of Revenue, P.O. Box 329, Jefferson City, MO 65105-0329.
- If you expect a refund or owe nothing: Missouri Department of Revenue, P.O. Box 500, Jefferson City, MO 65105-0500.
Attach Form MO-A, copies of your W-2s, and any other supporting schedules. Sign the return before you drop it in the mail, and use a method with tracking so you can prove it went out before the deadline. Paper returns go through manual review and can take several weeks during peak season.
Deadlines and Extensions
Missouri returns are due April 15 of the year after the tax year. If the 15th falls on a weekend or holiday, the deadline moves to the next business day. The return and any payment are both due that day.
If you cannot finish by April 15 and you have an approved federal extension, Missouri grants you an automatic extension too. You do not need to file a separate state form as long as you do not expect to owe additional Missouri tax or you anticipate a refund. Just attach a copy of your federal extension when you eventually file the Missouri return.6Missouri Department of Revenue. Form MO-60 – Application for Extension of Time to File
You do need to file Form MO-60 if you expect to owe Missouri tax and need more time, or if you want a state extension without a federal one. An approved MO-60 pushes your filing deadline to October 15. An extension to file is not an extension to pay. Estimate what you owe and send that payment with Form MO-60 by April 15 to avoid penalties.6Missouri Department of Revenue. Form MO-60 – Application for Extension of Time to File
Estimated Tax Payments
If you have income that is not subject to withholding, such as self-employment earnings, rental income, or investment gains, you may need to make quarterly estimated payments using Form MO-1040ES. Missouri requires estimated payments if you expect to owe $100 or more in state tax for the year.7Missouri Department of Revenue. Form MO-1040ES – Declaration of Estimated Tax for Individuals The quarterly deadlines are April 15, June 15, September 15, and January 15 of the following year.
What Late Filing or Late Payment Costs
Missouri charges separate penalties for filing late and paying late, and both can apply at once.
File after the deadline without an approved extension and the state adds 5 percent of the unpaid tax per month, or partial month, up to a maximum of 25 percent.1Missouri Department of Revenue. FAQs – Individual Income Tax File on time but fall short on payment, and if the shortfall is from negligence or disregard of tax rules, the penalty is a flat 5 percent of the unpaid amount. If any part of the underpayment is from fraud, the penalty rises to 50 percent of the deficiency.8Missouri Revisor of Statutes. RSMo Section 143.751 – Failure to Pay Tax
Interest runs on top of penalties. The 2026 rate is 7 percent, accruing from the original due date until the balance is paid.9Missouri Department of Revenue. Statutory Interest Rates
After You File: Refunds and Paying a Balance
Once your return is in, you can check its status with the “Where’s My Refund” tool on the Missouri Department of Revenue website. You will need your Social Security number and the expected refund amount. Electronic returns usually process in seven to ten business days; paper returns can take several weeks during peak filing season.
If you owe, you have two main payment options:
- Pay electronically through the MyTax Missouri portal with a bank transfer or credit card.
- Mail a check or money order payable to the Missouri Department of Revenue, with a payment voucher, to P.O. Box 329, Jefferson City, MO 65105-0329.5Missouri Department of Revenue. Individual Income Tax Contact Information
Payment is due April 15 either way, regardless of any filing extension.
Credits Worth Checking Before You File
Missouri’s income tax uses a graduated structure topping out at 4.7 percent on taxable income above $9,191 for the 2025 tax year.10Missouri Department of Revenue. 2025 Individual Income Tax Year Changes A few credits can reduce what you actually owe.
The Property Tax Credit is for senior citizens and people who are 100 percent disabled. Qualifying homeowners can receive up to $1,100 and renters up to $750, based on property taxes or rent paid and total household income. Renters must rent from a property that pays property taxes to qualify.11Missouri Department of Revenue. Property Tax Credit You claim it separately on Form MO-PTC.
Missouri also offers credits for adoption expenses, contributions to certain organizations, and other qualifying activities. The full list, with eligibility rules, is in the Form MO-1040 instructions for the tax year you are filing.