How to File for a Missouri Tax Extension

A Missouri tax extension provides additional time to submit your state tax return, but it is not an extension of the time to pay any taxes you may owe. The deadline for paying your tax liability remains the same, regardless of whether you secure an extension to file. Failing to pay by the original due date can result in penalties and interest charges, even with a valid filing extension in place.

Understanding the Missouri Extension Process

Missouri simplifies the extension process by linking it to the federal system. If you have received an approved federal extension from the IRS by filing Form 4868, Missouri automatically grants you a corresponding extension to file your state return. If you do not expect to owe any additional state income tax, no separate Missouri extension form is required. You will simply attach a copy of your federal extension to your Missouri return when you file it.

For taxpayers who do not need a federal extension but require one for their Missouri return, a separate application is necessary. This is also the case for any taxpayer who expects to owe Missouri income tax, regardless of their federal extension status. In these situations, you must file a specific state form to request the extension.

Information and Forms for Paying Your Estimated Tax

Before you file for an extension that involves a payment, you must first estimate your total tax liability for the year. This involves calculating your expected Missouri adjusted gross income and applying the relevant tax rates to determine the total tax you anticipate owing. From this total, you subtract any state taxes already paid through employer withholding or quarterly estimated payments. The remaining amount is the balance you must pay by the original April 15th tax deadline.

The primary document for this process is Form MO-60, Application for Extension of Time to File. This form is used for submitting your payment to the Missouri Department of Revenue. To complete Form MO-60, you will need to provide your name, address, and Social Security Number, as well as the same information for your spouse if filing jointly. The form requires you to enter your tentative tax amount, total payments and credits, and the final amount you are paying.

Submitting Your Payment and Completing the Process

Once you have calculated your estimated tax and filled out Form MO-60, you have two methods for submitting your payment. You can mail the completed Form MO-60 along with a check or money order for the amount of tax due to P.O. Box 3400, Jefferson City, MO 65105-3400. Ensure the payment is postmarked by the original tax deadline.

Alternatively, you can make your payment electronically through the Missouri Department of Revenue’s online payment portal with an electronic check or a credit or debit card. Securing the extension gives you until October 15 to file your completed Missouri tax return, Form MO-1040. You must still file this final return by the extended deadline.

Consequences of Not Paying by the Deadline

Failing to pay your tax liability by the original due date has direct financial consequences, even if you have a valid extension to file your return. Missouri’s Failure to Pay Penalty is a one-time charge of 5% on the unpaid tax amount.

In addition to the penalty, interest is charged on any unpaid tax balance. Interest accrues on the underpaid amount from the original due date of the return until the date the tax is paid in full. The annual interest rate can fluctuate.