When Can I File Missouri State Taxes? Key Deadlines and Tips

Filing state taxes in Missouri is an important annual task for residents and businesses. Missing deadlines or failing to follow proper procedures can lead to penalties, delays in refunds, or unnecessary stress. Knowing key deadlines, early filing options, extension procedures, and how to track your return ensures compliance and avoids common mistakes.

Official Filing Window and Deadlines

Missouri’s state tax filing period aligns with the federal tax season, opening on January 29, 2024, and closing on April 15, 2024. If April 15 falls on a weekend or holiday, the deadline moves to the next business day.

Returns must be filed using the appropriate forms, such as the MO-1040 for individuals. The Missouri Department of Revenue (DOR) processes returns electronically and by mail, though e-filing is encouraged for faster processing and greater accuracy. The state partners with tax preparation software providers, allowing eligible taxpayers to file for free through the Missouri Free File program.

Missing the April 15 deadline without an approved extension results in penalties. Missouri imposes a late filing penalty of 5% of the unpaid tax per month, up to 25%. Interest also accrues on unpaid balances, with the 2024 rate set at 6%. These charges add up quickly, making timely filing essential.

Early Submission Details

Filing early can speed up refunds, reduce the risk of tax-related identity theft, and allow time to fix errors. Electronically filed returns are typically processed within two weeks, while paper returns take six to eight weeks.

Tax-related identity theft is a risk for late filers. Fraudsters may attempt to submit false returns using stolen information, but filing early ensures the legitimate return is processed first.

Submitting early also allows time to correct mistakes. If the DOR identifies missing information or discrepancies, taxpayers can resolve them before the deadline, avoiding delays and penalties.

Extension Filing Procedure

Missouri taxpayers needing more time can request a six-month extension, moving the deadline to October 15. However, this only extends the time to file, not to pay. Taxes owed after April 15 begin accruing interest and penalties, so estimating and paying any expected balance when requesting an extension is recommended.

Taxpayers who receive a federal extension through IRS Form 4868 automatically get a Missouri state extension and do not need to submit a separate request. Those without a federal extension must file Missouri Form MO-60 by April 15. This form can be submitted online or by mail.

Even with an extension, waiting until the last minute increases the risk of errors or missed deductions. Taxpayers with complex situations, such as self-employment income or rental properties, may benefit from using tax software or consulting a professional.

Late Filing Implications

Failing to file on time can lead to financial consequences beyond penalties. If a taxpayer is owed a refund but does not file, Missouri law allows only three years from the original due date to claim it. After that, the refund is forfeited to the state.

For those who owe taxes, Missouri applies interest to unpaid balances based on the annual rate set by law. If payment is not made within 60 days of the due date, the state may issue a tax lien. A lien places a legal claim against property, including real estate, vehicles, and financial assets, affecting credit and complicating future transactions.

Checking Your Return Status

Tracking your return status helps ensure timely processing and identifies potential issues. The Missouri DOR provides an online tool called “Where’s My Refund?” that requires a Social Security number, filing status, and the exact refund amount claimed.

For electronic filers, updates typically appear within five business days, while paper filers may need to wait several weeks. Delays can occur due to errors, missing documentation, or additional verification requirements. If income figures do not match employer-reported data, the DOR may request further information.

To avoid delays, double-check all entries before submission and ensure all required forms are included. If a return remains unprocessed beyond the typical timeframe, contacting the DOR or checking the online portal can provide further clarity.