Simplify Your Missouri State Tax Return: Essential Tips and Resources

Filing your Missouri tax return for 2023 doesn’t have to be a complicated process. Whether you're a first-time filer or a seasoned taxpayer, understanding how to file, what forms to use, and when to submit your return can save you time, money, and frustration. This guide is designed for individuals and small business owners who want a clear, step-by-step overview of how to complete and file their income tax return for Missouri.

We’ll walk you through who must file, which forms apply to your situation, and how to prepare your return using the correct figures from your federal tax return. You’ll also learn about estimated tax payments, filing deadlines, available deductions, and how to calculate any balance due or refund owed. Whether you’re filing on paper or choosing to e-file, we’ll explain the entire process in beginner-friendly language.

By the end, you’ll know how to request an extension, avoid common filing mistakes, and track your refund status through the Missouri Department of Revenue. If you're unsure whether you owe taxes or qualify for credits, this guide offers practical examples and helpful instructions. You can confidently complete your tax filing with the proper guidance and access to the correct forms and resources.

Who Needs to File a Missouri Tax Return?

Missouri requires many individuals and small business owners to file a state tax return, depending on residency status, income level, and whether they must file a federal income tax return. Knowing whether you’re required to file helps ensure you stay compliant and avoid penalties or missed refunds. The rules are essential if you live in multiple states, have Missouri-based income, or are self-employed.

Full-Year Residents

If you lived in Missouri for the entire year, you are required to file a Missouri tax return if all of the following conditions are true:

You were a full-year resident of Missouri for the 2023 tax year.
You are required to file a federal income tax return for 2023.
You earned $1,200 or more in Missouri adjusted gross income during the year.

Part-Year Residents and Nonresidents

If you only lived in Missouri part of the year or earned income from Missouri sources while living elsewhere, you may still be required to file a state tax return:

You must file a claim if you are a part-year resident of Missouri and have earned $1,200 or more in Missouri-source income.
You must also file if you were a nonresident who earned $600 or more from Missouri-based sources, such as wages from a Missouri employer or rental income from property in the state.
In both situations, you are only required to file a Missouri return if you also need to file a federal return.

Other Common Filing Situations

Some taxpayers must file a Missouri return even if their income is below the standard thresholds:

You must file a return to pay the balance if you owe taxes due to underpayment, missed estimated tax payments, or insufficient withholding.
If you expect a refund due to overpayment or available tax credits, filing a return allows you to claim that refund.
If you are self-employed or part of a partnership that earned Missouri income, you are generally required to report and pay taxes on that income.
If you received income from a Missouri employer, own Missouri rental property, or operate a business within the state, you must report that income even if you reside elsewhere.

If you're unsure about your filing status, it’s beneficial to refer to the instructions on Form MO-1040 or consult a tax preparer. Filing a return, even when not strictly required, may help you recover money owed to you through credits or withheld taxes.

Key Missouri Tax Deadlines and Changes for 2023

Staying on top of Missouri’s tax deadlines helps prevent costly penalties, interest charges, and processing delays. Knowing the due dates is critical to successful tax filing, whether you owe taxes, expect a refund, or submit an extension request.

Important Tax Filing Deadlines for 2023

The original due date to file your 2023 Missouri state tax return is April 15, 2024. If this date falls on a weekend or holiday, the deadline shifts to the next business day.
If you need more time to prepare your return, you can file Form MO-60 to request an extension. You may also qualify for an automatic extension if you’ve filed a federal extension with the IRS.
It’s important to note that an extension allows more time to file your return, not more time to pay any unpaid tax. All tax payments are still due by April 15, 2024.
If you are required to make quarterly estimated tax payments, they were due on April 15, June 15, September 15, 2023, and January 15, 2024.

Tax Law Updates for the 2023 Filing Year

Missouri’s standard deductions for 2023 have been adjusted to match federal deduction amounts. This includes changes based on your filing status, such as single, married filing jointly, or head of household.
If you receive military retirement income, you can deduct up to 80% of that income on your Missouri return in 2023. This percentage will increase to 100% for the 2024 tax year.
Depending on their income level and filing status, taxpayers age 62 or older may still qualify for pension and Social Security exemptions.

You can always refer to the Missouri Department of Revenue or the current year’s instructions on Form MO-1040 for the latest updates that may affect your tax filing.

Which Missouri Tax Forms You’ll Need

Choosing the proper tax forms is the first step in preparing an accurate Missouri tax return. The form you need depends on your income level, residency status, available deductions or credits, and whether your situation is complex or straightforward.

Form MO-1040 – Standard Individual Income Tax Return

You should use Form MO-1040 if any of the following apply to your situation:

You plan to claim tax credits, including those listed on Form MO-TC, such as business development or historic preservation credits.
You must report additions or subtractions to income—like military pay or retirement income—on Form MO-A.
You are a nonresident, a part-year resident, or a military member who earned income in Missouri.
You are filing an amended return to correct a previously submitted Missouri tax return.

Form MO-1040A – Simplified Return Option

Form MO-1040A is a shorter version of the standard return and may be used if all the following conditions are met:

You are a full-year Missouri resident and earned all your income from Missouri sources.
You are not claiming notable tax credits or making any income modifications.
You only take the standard deduction and do not itemize deductions such as mortgage interest or property tax.

Additional Forms and Schedules You May Need

Depending on your specific circumstances, you might also need to include these supporting forms:

Form MO-A is required if you have any adjustments to your federal adjusted gross income, such as interest from U.S. bonds or military retirement benefits.
Form MO-CR allows you to claim a credit for taxes paid to another state if you are a Missouri resident with out-of-state income.
Form MO-NRI helps calculate how much of your income is taxable in Missouri if you were a nonresident or part-year resident.
Form MO-TC consolidates various tax credits you might be eligible for based on income, housing, or business activity.
Form MO-60 must be filed by April 15 if you request an extension and did not file a federal extension.

Using the correct forms the first time helps ensure your return is complete, avoids delays, and gets you one step closer to your refund or resolving any balance due.

Step-by-Step Instructions to Complete Your Missouri Return

Once you’ve determined that you need to file a Missouri tax return and have the proper forms ready, the next step is to work through the process from start to finish. These step-by-step instructions are designed to make the tax filing process manageable, even if you're not a tax expert.

Step 1: Gather Your Personal and Financial Records

Before filling out your forms, make sure you have all the necessary documentation in one place:

Gather Social Security numbers for yourself, your spouse (if applicable), and any dependents listed on your return.
Collect all Form W-2s from employers to report your wages and tax withholdings.
Include any Form 1099s for dividends, retirement income, unemployment benefits, or self-employment income.
Retrieve Schedule K-1 forms if you earned income from partnerships or S corporations.
Organize your receipts and records for deductions, including property taxes, charitable donations, and mortgage interest.
Have your bank account and routing number ready to receive your refund through direct deposit.

Step 2: Complete Your Federal Return First

Missouri calculates its state taxes using your federal adjusted gross income (AGI) from your federal income tax return. Complete your federal return before completing the Missouri forms, as you’ll need to transfer key information such as AGI, tax liability, and filing status.

Step 3: Fill Out Form MO-1040 or MO-1040A

With your federal return complete, you can now begin your Missouri return:

On Line 1 of Form MO-1040, enter the federal AGI from your IRS Form 1040.
Use Form MO-A to enter any additions or subtractions, such as tax-exempt interest or military or retirement income deductions.
Calculate your Missouri adjusted gross income by combining your federal AGI with any applicable income modifications.

Step 4: Apply Credits, Deductions, and Exemptions

Now that you’ve calculated your income:

Select either the standard deduction or itemize your deductions, depending on which provides the greater benefit.
Use Part 3 of Form MO-A to apply exemptions for Social Security income, public pension benefits, or long-term care insurance premiums if you qualify.
Refer to the Missouri tax tables to determine your base income tax.
Apply any eligible tax credits from Form MO-TC or Form MO-CR, and reduce your total tax accordingly.

Step 5: Determine If You Owe or Expect a Refund

Add up the taxes already paid through paycheck withholding (as shown on your W-2s) or estimated tax payments made throughout the year.
If your payments exceed your total tax, you’ll receive a refund. Be sure to include your direct deposit info for the fastest processing.
If you owe a balance, be prepared to submit payment by the April due date. Failure to pay on time can result in penalties, interest, and additional fees.

Following these steps carefully helps reduce filing errors, increases your chances of receiving a maximum refund, and makes the entire tax process more efficient. If your situation is complex or you're filing for multiple income types, consider working with a tax preparer or using reputable tax software programs for added support.

How to File Your Missouri Tax Return

Once you’ve completed your Missouri tax return, the next step is to choose how you want to file it. Missouri offers multiple filing methods, including electronic filing and traditional paper submission. Your preferred method may affect how quickly your return is processed and how soon you receive your refund.

Filing Electronically (E-File)

Many taxpayers prefer to e-file their returns for faster processing, fewer errors, and easier access to refund tracking.

Filing online allows you to submit your return 24/7 from your computer or mobile device using approved software or filing services.
If you’re eligible, Missouri’s Free File program provides no-cost filing options through partner companies for qualified individuals. Visit the Department of Revenue website to find out if you qualify.
Electronic filing can reduce math errors, prevent missing form attachments, and enable the direct deposit of refunds into your bank account.
You will receive confirmation within five business days once your return is accepted.

Filing a Paper Return

If you prefer not to file electronically or do not qualify for free e-filing, you can mail your return to the appropriate Missouri Department of Revenue address:

For refunds or no balance due, mail your return to P.O. Box 500, Jefferson City, MO 65105-0500.
If you owe taxes and are including a payment, send your return to P.O. Box 329, Jefferson City, MO 65105-0329.
Paper returns typically take 6 to 8 weeks to process, and errors or missing documents can further delay this.

Regardless of your filing method, always sign and date your return. Include any required attachments such as W-2s, federal return copies, and supporting schedules. For the fastest and most accurate experience, many tax pros recommend e-filing with the help of a qualified tax preparer or secure filing software.

How to Pay Your Missouri State Taxes

If your tax return shows that you owe Missouri taxes, paying on time is essential to avoid late fees, interest, and other penalties. The Missouri Department of Revenue offers multiple payment methods to make the process convenient.

Online Payment Options

The easiest way to pay your taxes is through Missouri’s official payment portal, which supports two main options:

E-Check (Electronic Bank Draft): This method requires your bank account and routing number. It has a low convenience fee of $0.50 and typically processes within three to four business days.
Credit or Debit Card: You can pay using a major credit card such as Visa, MasterCard, Discover, or American Express. This method includes a 2.0% plus $0.25 fee and may take five to six business days to post.

These online services are secure and accessible 24/7. If you use third-party software to file your return, you can schedule your payment electronically during the filing process.

Payment Deadlines and Penalties

Even if you request a filing extension, the original payment due date is still April 15, 2024.
If you fail to pay by this date, Missouri may assess a 5% penalty on any unpaid tax, plus additional interest that accrues daily.
Late filing can result in a penalty of 5% per month, up to a maximum of 25%.
If you cannot pay the full amount, request a payment plan through the Department of Revenue’s website to avoid collections or enforcement actions.

Paying your balance on time helps avoid unnecessary fees and protects your financial standing. Consider consulting a tax expert if you need help calculating what you owe or navigating payment options.

How to Track Your Refund or Balance Due

After you’ve filed your Missouri tax return and submitted payment (if required), you can monitor the status of your refund or confirm whether you still owe a balance. Missouri provides a free and easy-to-use Return Inquiry System online.

Using the Return Inquiry System

To check your refund or balance due, visit the Missouri Department of Revenue website and navigate to the “Check Return Status” page. You’ll need the following information:

The primary Social Security number is listed on your return.
Your filing status, such as single, head of household, or married filing jointly.
The exact amount of your expected refund or balance due is in whole dollars.

The system is available 24/7 and typically provides updates for electronically filed returns within five business days. If you filed a paper return, allow at least three to four weeks before checking your status.

Other Refund and Notification Options

You can receive text or email updates when your return status changes.
Select direct deposit when filing to receive your refund as quickly as possible.
If you prefer to call, Missouri offers an automated refund hotline at (573) 526-8299 for refund-related questions.

Tracking your return helps you confirm that it was received and processed successfully and provides peace of mind about your refund or remaining tax balance. If you notice delays, verify that all required forms were included and properly completed.

Common Mistakes to Avoid on Your Missouri Return

Even minor errors on your Missouri state tax return can lead to delayed refunds, incorrect tax bills, or penalties. By understanding the most common mistakes taxpayers make each year, you can take simple steps to ensure your return is accurate, complete, and processed without hassle.

Frequently Overlooked Issues

Many taxpayers forget to sign and date their return. An unsigned paper return is considered incomplete and will not be processed until corrected.
Failing to include necessary attachments, such as W-2s, 1099s, or pages from your federal return, may delay your refund or cause the state to reject your return entirely.
Entering an incorrect federal adjusted gross income—a key figure from your federal income tax return—can throw off your entire Missouri tax calculation. Always double-check this value before submitting.
Choosing the wrong filing status is another frequent mistake. Your Missouri filing status must match the one selected on your federal return unless you claim a special credit or exemption.
Simple math errors can lead to underpayment or overpayment. Using Missouri’s fillable forms, official tax software, or a tax preparer can reduce calculation mistakes.
If you filed an extension, remember to check the extension box on your return and attach Form MO-60 or your federal extension form. Forgetting to do these tasks may result in a late filing penalty.

Avoiding these issues can help you claim your refund faster, reduce interest or penalties on unpaid tax, and ensure your return is accepted the first time.

Final Filing Checklist

Before you submit your Missouri tax return, it’s a good idea to go through a final checklist to ensure everything is complete and accurate. This simple review can help you avoid last-minute errors and reduce the need to amend your return later.

Pre-Filing Review

Confirm that your federal return is complete, since Missouri calculations rely on your federal adjusted gross income.
Ensure you’ve selected the correct Missouri tax form (MO-1040 or MO-1040A) based on your filing status and financial situation.
Double-check that you’ve reported all sources of income, including wages, interest, retirement distributions, and self-employment earnings.
Verify that your filing status matches the one used on your federal return.
Confirm that Social Security numbers for yourself, your spouse, and dependents are correct.

Required Attachments and Supporting Documents

Include copies of your W-2 forms from employers and 1099s for other income types.
Attach pages 1 and 2 of your federal Form 1040 if you claim certain deductions or losses.
If claiming a pension or Social Security exemption, include Form 1099-R and SSA-1099, respectively.
Attach any applicable supporting forms such as MO-A, MO-CR, MO-NRI, or MO-TC.

Final Submission and Payment Details

Make sure your return is properly signed and dated. If you are filing jointly, both spouses must sign the return.
If you expect a refund, confirm that your bank account and routing numbers are accurate for direct deposit.
If you have an outstanding balance, please include your payment method or submit it online before the due date.
Keep a printed or digital copy of your return and all supporting documents for at least four years in case of an audit or correction.
If you filed an extension, ensure the extension box is marked and supporting documentation is attached.

Following this checklist will give you confidence that your return is complete and compliant—and may help you receive your refund or resolve any balance more quickly.

Frequently Asked Questions (FAQs)

How can I file my Missouri state tax return for free?

You may be able to file your Missouri state tax return for free through the state’s Free File program. Several approved companies offer free tax filing services to eligible taxpayers based on income and filing status. These tools help you prepare, complete, and e-file your return. Visit the Missouri Department of Revenue website to access qualifying options and follow the official instructions for the current year based on the guidelines.

Do I need to include my federal tax return with my Missouri filing?

Yes, when you file your Missouri tax return, you must include a copy of your federal tax return. Missouri uses the federal return to verify income, apply deductions, and determine credits. If you claim losses, attaching pages 1 and 2 of your federal income tax return along with any required forms is essential. Omitting federal documents may delay your refund or result in penalties.

What should I do if I missed the original due date?

If you miss the original due date for filing your tax return, please submit it at your earliest convenience to minimize penalties and interest on any unpaid tax. You can request an extension to file, but your obligation to pay taxes remains. Late estimated tax payments or underpaid amounts may also result in additional fees. For help, consult a tax preparer or refer to state filing guidance.

How do I track my tax refund from Missouri?

To track your Missouri tax refund, visit the Department of Revenue’s online Return Inquiry System. You’ll need your Social Security number, filing status, and the refund amount in whole dollars. If you e-file and choose direct deposit, your money may arrive faster—usually within 7–14 business days. Paper filers should allow more time. Ensure your bank account info is accurate and all required forms are included.

Do I have to make estimated tax payments during the year?

You may need to make estimated tax payments if your income is not subject to withholding, like self-employment or partnerships. This helps avoid underpayment penalties at tax filing time. Missouri generally follows IRS rules for estimated tax schedules. Use a trusted software program or work with tax experts to calculate your quarterly payments and stay compliant. Payments can be made online through a secure financial institution.

What happens if I owe taxes but can’t pay the full amount?

Missouri allows you to set up a payment program if you owe taxes but can’t pay everything by the due date. You may request a balance payment plan through the Department of Revenue’s website. Be aware that interest, penalties, and fees may apply. Filing your return on time is essential, even if you can’t immediately pay. For example, when planning or seeking expert help, consult a tax preparer or trusted service.

How to File Your Missouri Tax Return for 2023: Step-by-Step Guide for Individuals and Small Businesses