Missouri Employer Tax Information
To sign up for Square’s online payroll services in Missouri, you must be registered with the Missouri Department of Revenue and Department of Labor and Industrial Relations so we can pay and file your state taxes.
| Agency | Required Tax Information | Format |
| Missouri Department of Revenue | Missouri Withholding Account Number | XXXXXXXX (8 digits) |
| Missouri Department of Labor and Industrial Relations | Missouri Employer Account Number | XX-XXXXX-X-XX (10 digits) |
| Missouri Contribution Rate | X.X% |
Missouri New Employer Registration
Missouri Withholding Account Number & Employer Account Number
Register online as a new business.
You will receive both your Withholding Account Number and Employer Account Number within 2 weeks.
Missouri Contribution Rate
If you are unsure of your rate, contact the agency at (573) 751-1995. See additional instructions below on how to locate your rate.
St. Louis Earnings Tax Registration
As an employer doing business in St. Louis, you are required to remit two local taxes: St. Louis Earnings Tax and St. Louis Payroll Expense Tax. For Square Payroll to file and pay these taxes, you need to register as a new business with the City of St. Louis Collector of Revenue.
Kansas City Business Registration
Employers in Missouri must withhold Earnings Tax from employees earning wages in certain local tax jurisdictions, including Kansas City. For Square Payroll to file and pay your Kansas City taxes, you need to register as a new business online with the Kansas City Revenue Division.
Find Your Missouri Tax ID Numbers and Rates
Missouri Withholding Account Number
You can find your Withholding Account Number on any previous quarterly return, or on any notices you have received from the Department of Revenue.
If you’re unable to locate this, contact the agency at (573) 751-8750.
Missouri Employer Account Number
You can find your Employer Account Number on any previous quarterly report, or on any notices you’ve received from the Department of Labor and Industrial Relations.
If you’re unable to locate this, contact the agency at (573) 751-1995.
Missouri Contribution Rate
You can find your Contribution Rate on the Rate Notice sent by the Department of Labor and Industrial Relations in November.
If you’re unable to locate this, contact the agency at (573) 751-1995.
Missouri Payroll Tax Details
Square Payroll processes the following per the frequency below to the listed state agencies:
| Agency | Filing | Frequency |
| Missouri Department of Revenue | Withholding Payment | Per Pay Run |
| Withholding Filing (Form MO-941) Note: Square Payroll only supports businesses who have a monthly filing frequency for Form MO-941. If you are not currently required to file and pay this tax on a monthly basis, please file Form 126 to request to change to the monthly requirement with the state. | Monthly | |
| State W-3s | Annual | |
| W-2 Reporting | Annual | |
| St. Louis Collector of Revenue | St. Louis City Withholding and Payroll Expense Tax Filing/Payment (Forms W-10/P-10) | Quarterly |
| St. Louis W-2 Reporting | Annual | |
| St. Louis Annual Reconciliation | Annual | |
| Kansas City Revenue Division | Kansas City Withholding Tax Payment (Form RD-130) | Per Pay Run |
| Kansas City Withholding Tax Filing (Form RD-110) | Quarterly | |
| Kansas City Annual Withholding Tax Filing (Form RD-113) | Annual | |
| Kansas City W-2 Reporting | Annual | |
| Missouri Department of Labor and Industrial Relations | Unemployment Insurance Payment | Quarterly |
| Unemployment Insurance Filing | Quarterly | |
| Missouri Department of Social Services | New Hire Reporting | Per New Employee |
Exemption from St. Louis Payroll Expense Tax
Non-profit organizations are typically exempt from filing and paying St. Louis Payroll Expense Tax. To claim exemption, you must send a copy of your Letter of Determination issued by the IRS to the Collector of Revenue.
For more information, read these FAQs or contact the Office of the Collector of Revenue at (314) 622-4111.