Missouri Payroll Tax: Withholding, Unemployment, and Local Taxes

Missouri payroll taxes fall into three layers. At the state level, employers withhold Missouri income tax from every paycheck (topped at 4.7% for 2026) and pay state unemployment tax on the first $9,000 of each worker’s annual wages. On top of that, federal FICA and FUTA apply to every employer in the state. And if you have workers in Kansas City or St. Louis, each city charges a 1% earnings tax, with St. Louis adding a 0.5% payroll expense tax that comes out of the employer’s pocket rather than the employee’s.

Missouri Income Tax Withholding

Any employer paying wages for work performed in Missouri must withhold state income tax, regardless of where the business itself is located.¹ How much you withhold depends on the information the employee gives you on Form MO W-4 and on Missouri’s graduated withholding tables. The MO W-4 no longer uses the old allowances system; employees either use the standard calculation or designate a specific dollar amount per pay period.²

For 2026, the top withholding rate is 4.7%, and it kicks in at modest income levels — roughly $766 per week for a single filer claiming standard deductions.³ That rate has been stepping down under scheduled reductions. Missouri treats employers as fiduciaries holding public funds, so if you withhold the wrong amount, you can be held personally liable for the shortfall plus interest.

Filing Frequency

Missouri assigns each employer a filing frequency based on how much tax you withhold:⁴

Quarter-monthly if you withhold $9,000 or more per month for at least two months in the prior year. Payments are due within three banking days after each quarter-monthly period ends.
Monthly if you withhold $500 or more per month for at least two months in the prior year. Returns are due by the 15th of the following month.
Quarterly if you withhold at least $100 in any quarter but don’t meet the monthly threshold. Due dates are April 30, July 31, October 31, and January 31.
Annual if you withhold less than $100 per quarter across the entire prior year.

Whatever your frequency, you report on Form MO-941 and file through MyTax Missouri at mytax.mo.gov.⁵ The portal accepts ACH payments and confirms receipt on the spot.⁶

Workers Who Cross State Lines

Missouri has no reciprocal tax agreement with any neighboring state. If you employ someone who lives in Kansas or Illinois but works in Missouri, you withhold Missouri tax on the Missouri wages, and the employee claims a credit on their home-state return to avoid double taxation. When someone splits time between states, you allocate wages by where the work was physically performed. This is a common source of employer errors for businesses near state borders.

Federal Payroll Taxes

Federal payroll taxes apply to every Missouri employer and usually dwarf the state-level bill.

Social Security (OASDI): employer and employee each pay 6.2% on wages up to $184,500 in 2026.⁷
Medicare: both sides pay 1.45% on all wages with no cap. Employees earning over $200,000 owe an additional 0.9% surtax, but that piece is the employee’s alone.⁷
FUTA: employers pay federal unemployment tax at an effective rate of 0.6% on the first $7,000 of each employee’s wages, assuming Missouri’s unemployment trust fund stays in good standing and no credit reduction applies.⁸

The employer’s share of FICA alone runs 7.65% of every paycheck. Stack that with Missouri withholding and state unemployment, and payroll taxes become a real line in the budget.

Missouri Unemployment Tax

Missouri’s unemployment tax is paid entirely by the employer. It funds the state’s unemployment insurance trust, which pays temporary benefits to workers who lose their jobs through no fault of their own. For 2026, the taxable wage base is $9,000, so you owe SUTA only on the first $9,000 of each employee’s annual earnings.⁹

Your rate depends on your experience rating, which reflects how many former employees have drawn benefits against your account. Rates run from 0.0% to 6.0%, before any surcharges.⁹ A business with stable employment and few claims can eventually reach that 0.0% floor; heavy turnover pushes you toward the ceiling. The gap between the two rates works out to $540 per employee per year on a $9,000 base.

New Employer Rates

Without a three-year claims history, Missouri assigns a new-employer rate based on industry. For 2026, that rate is 2.376% for most industries, including construction, mining, and a catch-all “all others” category. Nonprofits get a lower starting rate of 1.0%.⁹ After enough history builds up, the state recalculates your rate from your actual claims experience.

SUTA Filing Deadlines

Quarterly wage reports and tax payments are due by the last day of the month after each quarter ends:¹⁰

Q1 (January–March): due April 30
Q2 (April–June): due July 31
Q3 (July–September): due October 31

li>Q4 (October–December): due January 31

If a due date lands on a weekend or holiday, the next business day counts as timely. Filing runs through the UInteract portal at uinteract.labor.mo.gov, which figures your taxable wages and contribution due once you enter or upload payroll data.¹⁰

Kansas City and St. Louis Earnings Taxes

Both Kansas City and St. Louis impose a 1% earnings tax on gross wages. Residents of either city owe the 1% on all wages, even if they commute to a job outside the city.¹¹ Non-residents owe the 1% only on wages earned for work physically performed within the city.¹² Employers with workers in either city must withhold this tax from paychecks and remit it to the municipality.

St. Louis Payroll Expense Tax

St. Louis adds a layer Kansas City does not. Employers in St. Louis pay a 0.5% payroll expense tax on all wages earned within the city, and it is not a deduction from employee pay. The business writes the check. Filing is quarterly on Form P-10, alongside employee earnings tax withholding on Form W-10, with the same April 30, July 31, October 31, and January 31 due dates as SUTA. Late payments trigger a 5% penalty per month, capped at 25%, plus 1% monthly interest.¹³

Workers’ Compensation Insurance

Workers’ compensation isn’t a tax, but it’s a mandatory payroll-related cost that catches many Missouri employers off guard. Any business with five or more employees must carry coverage. Construction is stricter: even one employee triggers the requirement. Family members count toward the employee threshold.¹⁴

Skipping coverage is expensive. Knowingly failing to insure is a class A misdemeanor with a fine of up to three times the annual premium the employer should have paid, or $50,000, whichever is greater. A second offense becomes a class E felony.¹⁵ Uninsured employers also lose the exclusive-remedy protection that normally caps employee injury claims at workers’ comp benefits, which means an injured worker can sue directly for the full range of damages.

New Hire Reporting

Missouri requires employers to report every new hire within 20 calendar days of the hire date. The rule applies to any employee who fills out a W-4.¹⁶ Reports go to the Missouri Department of Social Services, not the Department of Revenue. The state uses this data to enforce child support orders and to detect benefit fraud. You can file online through the Department of Social Services’ employer portal. Missing the 20-day window can result in penalties, and this is one of the most commonly overlooked payroll obligations for small businesses.

Accounts You Need Before You Can File

Three accounts have to be in place before your first payroll run:

A Federal Employer Identification Number (FEIN) from the IRS.
A Missouri withholding tax account with the Department of Revenue, set up online at dor.mo.gov.¹⁷
An unemployment tax account with the Department of Labor and Industrial Relations, set up through UInteract.

The state’s online registration portal lets you open the withholding and unemployment accounts in one session. Keep all three numbers accessible during every filing cycle; payments submitted under the wrong account create reconciliation problems that take months to unwind.

Penalties for Late or Wrong Filings

Missouri’s penalties compound quickly. For state income tax withholding:⁴

Late filing: 5% of the tax due per month or partial month, up to a maximum of 25%.
Late payment due to negligence: a flat 5% addition to the tax owed.
Quarter-monthly underpayment: a separate 5% penalty for each quarter-monthly period underpaid.
Interest: accrues daily at a rate the Department of Revenue sets each year.

These penalties stack. An employer who files late and underpays can face the filing penalty, the negligence penalty, and interest at the same time.⁵

Unemployment tax has its own penalty schedule. Miss a quarterly report and the penalty is 10% of contributions due or $100 (whichever is greater) for each month or partial month you’re late, capped at 20% of contributions due or $200 per quarter (whichever is greater). This penalty still applies even if you had no payroll that quarter or owe zero tax.¹⁰

1
Missouri Department of Revenue. FAQs – Withholding Tax
2
Missouri Department of Revenue. Form MO W-4 – Employees Withholding Certificate
3
Missouri Department of Revenue. 2026 Missouri Income Tax Withholding Table
4
Cornell Law Institute. Missouri Code 12 CSR 10-2.015 – Withholding of Tax
5
Missouri Department of Revenue. MO-941 Employers Return of Income Taxes Withheld
6
Missouri Department of Revenue. Employer Withholding
7
Social Security Administration. Contribution and Benefit Base
8
U.S. Department of Labor. FUTA Credit Reductions
9
Missouri Department of Labor and Industrial Relations. Tax Rates
10
Missouri Department of Labor and Industrial Relations. Quarterly Reports
11
City of Kansas City. Have You Paid Your KCMO Earnings Tax (E-Tax)?
12
City of St. Louis. Individual Earnings Tax Information
13
City of St. Louis. Employer Withholding and Payroll Expense Tax Information
14
Missouri Revisor of Statutes. RSMo 287.030
15
Missouri Department of Labor and Industrial Relations. Workers Compensation Fraud and Noncompliance
16
Missouri Department of Social Services. New Hire
17
Missouri Department of Revenue. Online New Business Registration