Missouri payroll tax registration runs through two state agencies: the Department of Revenue issues your withholding tax account, and the Division of Employment Security issues your unemployment insurance account. You can handle both in one online session through MyTax Missouri, or by mailing Form 2643 to the Department of Revenue. Register before your first payroll if you can, because the state backdates liability to the first day you paid wages.
When You Have to Register
Withholding and unemployment insurance have different triggers, and you may hit one before the other.
For withholding tax, there is no minimum. If you pay wages to anyone performing work in Missouri, whether or not they live in the state, you must have a withholding account with the Department of Revenue and must withhold state income tax from the first paycheck.1Missouri Department of Revenue. Employer Withholding
Unemployment insurance kicks in under Missouri Revised Statutes Section 288.032 when either of two things happens:
- You pay at least $1,500 in total wages during any single calendar quarter, or
- You have at least one worker for any part of a day in 20 different weeks within a calendar year. The weeks do not have to be consecutive.
Meeting either condition in the current or preceding calendar year makes you a liable employer.2Missouri Revisor of Statutes. Missouri Code 288.032 – Employer, Definition Of Agricultural labor and domestic services fall under separate thresholds and are excluded from this general calculation.3Missouri Department of Labor and Industrial Relations. Liability for Unemployment
What to Gather Before You Start
Incomplete applications stall. Have all of this ready:
- Your Federal Employer Identification Number (FEIN). You cannot complete Missouri registration without one.4Missouri Department of Revenue. Online New Business Registration
- Your Secretary of State file number. Your legal name on the application must match what is on file.
- The physical location where work is performed and any separate mailing address for tax correspondence.
- A plain-language description of what your business does and its major products or services. Missouri does not require an NAICS code on the form.5Missouri Department of Revenue. Missouri Tax Registration Application
- Full name, Social Security number, date of birth, title, and home address of every owner, officer, partner, or member. Corporations list all officers, LLCs list all members, and partnerships list all partners.
- The exact date your business first paid, or will pay, wages in Missouri. The state uses this to set the effective date of your account.
How to Submit the Application
Online Through MyTax Missouri
The Department of Revenue and the Division of Employment Security share an online registration system at MyTax Missouri. One session covers both withholding and unemployment insurance. Select the option to register a new business, work through the prompts, and the system validates entries as you go. You get a confirmation number on submission.4Missouri Department of Revenue. Online New Business Registration
Paper Application (Form 2643)
The Missouri Tax Registration Application, Form 2643, is available as a PDF on the Department of Revenue website. It covers sole proprietorships, corporations, partnerships, LLCs, and trusts, with a different section for each ownership type.5Missouri Department of Revenue. Missouri Tax Registration Application Mail the completed form to:
Missouri Department of Revenue
P.O. Box 357
Jefferson City, MO 65105-0357
Paper takes noticeably longer to process. If you need your account numbers to run your first payroll on schedule, file online.
What You Receive Back
You end up with two account numbers from two agencies.
The Department of Revenue issues an eight-digit Missouri Tax Identification Number for withholding.6Missouri Department of Revenue. No Tax Due Info Online registrations typically produce this within a few business days; paper can take several weeks. The Division of Employment Security separately issues your unemployment insurance account number.7Missouri Department of Labor and Industrial Relations. Unemployment Insurance Tax
The state also assigns a withholding filing frequency based on how much you expect to withhold:
- Monthly filing for employers withholding $500 to $9,000 per month
- Quarterly filing for employers withholding $100 per quarter to $499 per month
- Annual filing for employers withholding less than $100 per quarter
Your frequency arrives by mail along with your account details and a schedule of due dates.8Missouri Department of Revenue. Maintain Employer Withholding Tax You file withholding returns on Form MO-941.
Unemployment Insurance After Registration
Missouri’s unemployment insurance taxable wage base for 2026 is $9,000 per employee. You owe unemployment tax only on the first $9,000 of wages paid to each worker during the calendar year.9Missouri Department of Labor and Industrial Relations. Tax Rates New employers without claims history get a starting rate, currently around 2.4%, which adjusts over time based on experience rating. More unemployment claims from your former employees push your rate up.
Quarterly wage reports go to the Division of Employment Security, listing each covered employee’s wages. The full unemployment contribution is on the employer. You cannot deduct any of it from a worker’s pay.7Missouri Department of Labor and Industrial Relations. Unemployment Insurance Tax
New Hire Reporting
Registration is not the end of the paperwork on a new employee. Missouri requires employers to report every newly hired employee within 20 days of the start date, and this obligation runs separately every time you bring someone on. You also report employees returning to work after being separated for 60 or more consecutive days.10Missouri Department of Social Services. Frequently Asked Questions
The report goes to the Missouri New Hire Reporting Program and must include:
- The employee’s full name (first, middle, and last), address, Social Security number, and date of hire
- The employer’s corporate name, address, and FEIN (use the same FEIN you use for quarterly wage reports)
Employers who submit electronically must transmit reports in two monthly batches no more than 16 days apart.
Penalties for Skipping or Filing Late
For withholding tax, filing a return late triggers an addition to tax of 5% per month or partial month, capped at 25% of the tax due. If the failure to pay is due to negligence rather than intentional fraud, an additional 5% penalty applies to the unpaid amount. Interest accrues at the state’s statutory rate and compounds until the balance is paid.11Legal Information Institute. 12 CSR 10-2.015 – Withholding of Tax
Corporate officers and directors have personal exposure. Any officer, director, or employee with direct control over filing returns and making tax payments can be held personally liable for unpaid withholding tax, penalties, and interest. The corporate form does not shield responsible individuals from this liability.11Legal Information Institute. 12 CSR 10-2.015 – Withholding of Tax
Records to Keep
Keep all payroll tax records for at least four years after the tax becomes due or is paid, whichever is later. That covers federal returns, state withholding returns, unemployment filings, and the underlying wage and hour records. Many practitioners recommend seven years to account for other statutes of limitations that could reach beyond the standard audit window.
At a minimum, keep each employee’s name, address, Social Security number, dates of employment, wage amounts, tax withheld, and copies of all W-4 forms. If the Division of Employment Security or the Department of Revenue audits your account, those records are the first thing they ask for.