St. Louis County Business License: Merchant License and Occupancy Permit

Starting a business in unincorporated St. Louis County involves navigating a layered licensing system. Unlike some states, Missouri has no statewide business license requirement. Instead, St. Louis County administers its own county-level licenses, and many of the county's 88 incorporated cities add their own municipal requirements on top. This guide walks you through what you actually need as a county business owner and what you should expect to pay.

Overview: County vs. Municipal Licensing in St. Louis County

St. Louis County sits in the heart of the St. Louis metropolitan area. It contains both unincorporated land (directly under county governance) and 88 incorporated municipalities, each with their own local licensing rules. This complexity means you could owe a St. Louis County business license and a license in your city, depending on where you operate.

For unincorporated St. Louis County businesses, the county has two core requirements: a merchant license and a Certificate of Occupancy. If you incorporate or operate in one of the county's cities, municipal rules may also apply.

The St. Louis County Merchant License

What It Is and How Much It Costs

St. Louis County requires a merchant or manufacturer license for businesses throughout the county, including those inside its cities. The fee is a flat $5. This fee is set by Missouri state law for charter counties, which St. Louis County is.

The $5 fee covers the merchant license itself and is typically valid for the calendar year, though you should verify the exact renewal schedule and any grace periods with the county.

Who Needs It

Missouri law applies the merchant license requirement to businesses that sell goods, wares or merchandise in the county, and the manufacturer license to businesses that make goods there. Some common examples:

• Retail stores
• Restaurants and food service operations
• Contractors who sell materials as part of their work (confirm with the county)
• Manufacturers or wholesalers
• Wholesale distributors and other dealers in goods

The merchant license is separate from and in addition to any sales tax permit you may need to collect state and local sales tax. Both are typically required if you sell taxable goods or services.

Application and Administration

The St. Louis County Collector of Revenue traditionally administers the merchant license program. However, verify directly with the Collector's office whether applications are processed by the Collector, the County Assessor, or both, as administrative procedures can change. Contact the St. Louis County Assessor or Collector of Revenue to confirm the current application process.

Many county applications can now be handled online or by mail. You will typically need:

• Your business name and structure (sole proprietorship, LLC, corporation, etc.)
• Business address in unincorporated St. Louis County
• Description of business activity
• Owner or principal contact information

Processing is usually quick, often within days for straightforward applications.

Certificate of Occupancy for Unincorporated Areas

What It Is

Unincorporated St. Louis County businesses typically must also obtain a Certificate of Occupancy from the county. This is a separate document from the merchant license and certifies that your business location meets local zoning, building, and safety standards.

Why It Matters

The Certificate of Occupancy is a local land-use control. It ensures your planned business activity is permitted in the zoning district where you operate and that the property itself (and any improvements) comply with county building codes. Without it, you cannot legally operate an unincorporated county business.

How to Get It

The application process for a Certificate of Occupancy typically involves:

1. Check zoning. Verify that your business type is permitted in the zoning district of your property. St. Louis County maintains a zoning map and code; contact the county's planning staff if you are unsure.
2. Submit an application. The county's Transportation and Public Works department, which handles commercial building permits, processes occupancy applications. You will need your property address, business type, and sometimes a site plan or floor plan.
3. Possible inspection. For some business types, a health, building, or safety inspection may be required before the certificate is issued. This is especially common for food service, child care, or other regulated businesses.
4. Receive the certificate. Once approved and any inspections pass, you receive the certificate.

Verify the current fee and timeline with St. Louis County Transportation and Public Works, as these can vary by business type and property condition.

Renewal

Certificates of Occupancy typically need renewal if you change your business type or if the county requires periodic re-certification. Always ask when you apply whether renewal is automatic or requires action on your part.

County Business Personal Property Registration

What It Is

Missouri law also requires businesses in St. Louis County to register personal property used in the business with the county for property tax purposes. This is separate from the merchant license or Certificate of Occupancy.

What Counts as Business Personal Property

Personal property includes equipment, machinery, fixtures, and other business assets that are not real estate. Examples:

• Manufacturing or production equipment
• Delivery vehicles and commercial equipment
• Store fixtures and signage
• Office equipment and furniture
• Computers and other business technology

How It Works

You typically declare your business personal property to the St. Louis County Assessor's office. The Assessor assesses the value of the property for property tax purposes. You then pay property tax on that personal property as part of your county tax bill.

Verify the current filing deadline and exemption thresholds with the St. Louis County Assessor. Some businesses may be exempt based on asset value or business type.

The Relationship to Municipal Licensing

If your business is in one of St. Louis County's 88 incorporated cities or towns, you will likely owe a municipal business license in addition to the county merchant license. Municipal fees and requirements vary widely, and some cities have their own Certificates of Occupancy or zoning checks.

A few examples:

• Clayton, University City, and Webster each set their own licensing fees and rules.
• Smaller municipalities may charge a flat annual fee or a sliding scale based on business size.
• Some cities require separate health permits or inspections for food service.

Your first step should be to identify whether your property is in unincorporated St. Louis County or within a city. If you are unsure, contact the St. Louis County Assessor's office or enter your property address on the county's mapping tool. Once you know, reach out to the appropriate city or county office for a complete picture of your licensing obligations.

State-Level Requirements: No Statewide Business License

Missouri does not require a statewide business license. However, depending on your business structure and activity, you will still need to complete certain state-level filings:

Business Structure Registration

If you form an LLC or corporation, you must file Articles of Organization or Articles of Incorporation with the Missouri Secretary of State. LLCs pay a $50 filing fee; corporations pay $58. These filings are separate from the county merchant license.

Sales Tax Permit

If you sell taxable goods or services, you must register for a Missouri sales tax permit through the Department of Revenue. The permit is free to obtain but is required to legally collect sales tax. The state sales tax rate is 4.225%, and county and city taxes are added on top, so the combined rate in St. Louis County is higher and varies by location. You remit all of it to the Department of Revenue.

Register for a sales tax permit at https://dor.mo.gov/register-business/.

Employer Withholding and Unemployment Insurance

If you hire employees, you must also register with Missouri's Division of Employment Security for unemployment insurance and set up federal and state payroll withholding. These are separate registrations not tied to the county license.

The Timeline: How Long Does It Take

Once you have decided to locate in unincorporated St. Louis County, here is a realistic timeline:

• Days 1–3: Zoning check and Certificate of Occupancy application. Contact the Planning Department and apply for your Certificate. Simple applications (e.g., a home office) may be approved within a few days; others may take 1–2 weeks if an inspection is needed.
• Days 2–5: Merchant license application. Once you have your Certificate of Occupancy (or while waiting for it), apply for the merchant license through the Collector of Revenue. Expect approval within a few days.
• Days 1–5 (in parallel): State filings. If forming an LLC or corporation, file with the Missouri Secretary of State. Online filings are typically processed immediately; paper filings may take longer.
• Days 1–5 (in parallel): Sales tax permit. Register for a state sales tax permit if you are selling taxable items. This is usually approved within days.
• Day 1 onward: Property tax registration. File a business personal property declaration with the Assessor; property is assessed as of January 1 each year, so confirm the filing deadline with the Assessor.

In most cases, you can be fully licensed and ready to operate within 1–2 weeks, assuming no inspection delays or zoning issues.

Costs Summary

Here is what you can expect to pay for unincorporated St. Louis County licensing alone:

• County merchant license: $5
• Certificate of Occupancy: Fee amount not specified; verify with Planning and Development
• Business personal property registration: No filing fee, but you will owe property tax on the assessed value

If you also form an LLC or corporation, add $50 (LLC) or $58 (corporation) for the state filing. Sales tax registration is free.

If your business is in a municipality, add that city's licensing fee on top. Total startup costs are usually under $100 for licensing alone, not including property, equipment, or other business expenses.

Key Contacts and Resources

Save these contacts for your setup process:

• St. Louis County Assessor's Office: Personal property registration and property assessment
• St. Louis County Collector of Revenue: Merchant license application and administration (verify they handle applications directly)
• St. Louis County Transportation and Public Works: Certificate of Occupancy applications and commercial building permits
• Missouri Secretary of State: LLC and corporation filings (https://www.sos.mo.gov/business/corporations)
• Missouri Department of Revenue: Sales tax permit and state business tax information (https://dor.mo.gov/taxation/business/)

When you call county offices, confirm the current application process, fees, and whether procedures have changed. County administrations update processes regularly, and direct verification saves time and confusion.

Common Mistakes to Avoid

• Assuming county and city are the same. Always confirm whether your property is unincorporated or in a city; municipal requirements differ sharply.
• Skipping the Certificate of Occupancy. Some business owners focus on the merchant license and forget occupancy approval. Both are required in unincorporated areas.
• Confusing the merchant license with a sales tax permit. You need both if you sell taxable goods or services. The merchant license is a local business authorization; the sales tax permit is for tax collection.
• Neglecting business personal property registration. Failing to register personal property can result in missed filings and potential penalties. Register promptly after purchase.
• Delaying state filings. If you form an LLC or corporation, file with the Secretary of State before (or immediately after) applying for county and city licenses.

Disclaimer

This resource is informational and based on Missouri state law and St. Louis County procedures as of October 2026. It is not legal or tax advice. Business licensing requirements can change, and individual circumstances vary. Before taking action, consult the official websites and staff of the St. Louis County Assessor, Collector of Revenue, and Planning and Development offices. For complex situations, consult a Missouri attorney or CPA familiar with St. Louis County regulations.

Next Steps

1. Confirm your property is in unincorporated St. Louis County (or identify your city if it is incorporated).
2. Contact St. Louis County Planning and Development to verify zoning for your business type.
3. Apply for a Certificate of Occupancy if in an unincorporated area.
4. Apply for a county merchant license (or city license if applicable).
5. Register with the Missouri Secretary of State if forming an LLC or corporation.
6. Apply for a state sales tax permit if you sell taxable goods or services.
7. Register business personal property with the Assessor and file its annual declaration on time.

Once these steps are complete, you are licensed to operate your business in St. Louis County.