Section 143.225.9, RSMo, allows the Director of Revenue to require the use of an electronic funds payment system for employers required to pay employer withholding taxes on a quarter-monthly basis. Additionally, Section 143.221.1, RSMo allows the Director of Revenue to prescribe the form to be used for reporting withholding tax.

As a result, effective January 1, 2004, the Director of Revenue has mandated that all employers subject to the requirement of quarter-monthly payments shall both file and pay employer withholding tax electronically. If you are an employer subject to this requirement and use a payroll company to file and pay your employer withholding tax, the payroll company will be required to electronically file and pay on your behalf.

Currently, the department accepts two methods for electronic filing and payment:

Because of the electronic filing mandate, paper returns and payment vouchers for quarter-monthly filers will no longer be available. Corrected returns must still be filed by paper and are available for download (Form MO-941). Click here for payment due dates.

For additional information, please contact the Withholding Tax Section at (573) 751-8750 or email