St. Louis County, MO Business License Guide: County, Cities, and State Rules

St. Louis County license, tax, and permit layer

St. Louis County has several business-related offices, but not every business license issue is handled by the county. The county’s own licensing FAQ says the county Department of Revenue Licensing division is not involved in business licenses or special event permits. It points merchant licenses to the Assessor’s Office and says local business licenses are issued by the municipality where the business is located.

Merchant and manufacturer license layer

For many retail, wholesale, and manufacturing businesses operating in St. Louis County, the county merchant/manufacturer license and business personal property registration layer may matter. County materials for the Business Personal Property Registration and Merchant or Manufacturer License state that businesses and manufacturers operating within St. Louis County are required to register with the County Assessor’s Office.

Do not treat this as permission to open your location. County Assessor materials warn that issuance of a merchant or manufacturer license does not authorize occupancy of a building space. A separate occupancy, zoning, building, municipal license, or health permit may still be needed.

Start with the St. Louis County Assessor business personal property registration and merchant/manufacturer license information. If that page is unavailable, use the County Assessor or county customer service portal to ask for the current Business Personal Property Registration and Merchant or Manufacturer License instructions.

County licensing division is not the same as a general business license office

The county Department of Revenue Licensing division handles various county licensing functions, but its FAQ tells business owners that business licenses are not handled by that division. This is an important trap. If a municipality requires a local business license, the city or village may control that license even though the business has a St. Louis County address.

Start with the St. Louis County Department of Revenue Licensing page for county licensing links, but verify business licensing with the municipality and merchant/manufacturer licensing with the Assessor.

Planning and zoning in unincorporated St. Louis County

The St. Louis County Department of Planning provides countywide services and also municipal-type services for the unincorporated parts of the county. For a business in unincorporated St. Louis County, zoning can decide whether the activity is allowed at the site, whether a special procedure is needed, and whether a home occupation is allowed.

Use the St. Louis County Department of Planning and the county’s zoning verification and compliance information to check unincorporated property. The zoning verification page tells users to verify that the parcel is in unincorporated St. Louis County before requesting zoning verification or zoning compliance letters.

Commercial occupancy and building permits

Opening, moving into, remodeling, or changing the use of a commercial space may require county or municipal building and occupancy approval. St. Louis County commercial occupancy materials describe a Certificate of Use and Occupancy, sometimes called an occupancy permit, as required before moving into a vacant tenant space or building and opening for business.

Start with St. Louis County Commercial Building, Permits and Applications, and Commercial Occupancy pages. If your site is inside a municipality, also ask whether the city issues its own occupancy permit or contracts with St. Louis County for certain code services.

Health, food, and environmental permits

Food businesses should not rely only on a city business license or a county merchant license. St. Louis County Department of Public Health materials say the Food Code requires regular inspection of food establishments, and the retail health permit application states that no person may operate a restaurant without a current and valid permit issued by the Director of the Department of Public Health.

Food-related businesses should start with the county Food and Restaurants page, the food permit applications, and the St. Louis County Food Code. Temporary food vendors should also check the county temporary events food information.

Other businesses may need environmental or public health approvals for body art, public water recreation, waste hauling, tobacco or vapor product retail, air pollution, septic, or other regulated activities. Use the county permits and code enforcement page as a starting point.

City and municipal business license layer

If your business address is inside a municipality in St. Louis County, the local city, town, or village may control the local business license, business tax, occupancy, zoning, and local permit process. The county may still matter for merchant/manufacturer licensing, public health, property, or code services, but the city layer cannot be skipped.

Examples of municipal rules

Municipal rules are not identical across St. Louis County. For example:

• The City of Chesterfield business license page says commercial businesses and persons physically located and operating out of tenant space within Chesterfield city limits must obtain a city business license from the Department of Finance.
• The City of Clayton business license page says a commercial occupancy permit must be approved before applying for a business license.
• The City of Florissant permits and business license information includes business license renewal and application instructions through the city process.

These examples show why you must check the specific municipality for your address. Do not assume one St. Louis County city’s process applies in another city.

If your address is in the City of St. Louis

The City of St. Louis is not a St. Louis County municipality. It is a separate independent city. The city says any person who engages in business within the City of St. Louis is required to have a business license, and its business license page says all nonexempt businesses require a Graduated Business License. The city also has occupancy requirements and separate rules for different business types.

Use the City of St. Louis License Collector business license information if your address is inside city limits.

What to ask your municipality

When you contact a municipality in St. Louis County, ask about:

• business license or merchant license requirements;
• local business taxes, gross receipts taxes, or license fees;
• zoning approval, home occupation rules, and prohibited uses;
• commercial occupancy or certificate of occupancy requirements;
• building, electrical, plumbing, mechanical, and sign permits;
• fire inspection or fire district requirements;
• mobile vendor, peddler, solicitor, food truck, liquor, tobacco, alarm, short-term rental, or contractor rules;
• whether county approvals are also required.

DBA, fictitious name, and business name layer

In Missouri, a DBA is commonly called a fictitious name. This is a state filing, not a St. Louis County filing. The Missouri Secretary of State says a fictitious name is a name under which a person or business does business in Missouri that is different from the person’s or business’s true name. The Secretary of State also says filing a fictitious name registration does not give exclusive rights to the name.

Use the Missouri Secretary of State fictitious name FAQ if you plan to operate under a name that is not your legal name or registered entity name.

A fictitious name is not the same as a business license. It does not usually replace a city business license, county merchant/manufacturer license, health permit, sales tax license, professional license, zoning approval, or occupancy permit.

Missouri state registrations and taxes

Even if the local city or county says you are clear locally, you may still need Missouri state registrations. These are separate from local licenses.

Secretary of State entity registration

If you form an LLC, corporation, nonprofit corporation, limited partnership, or other registered entity, you generally deal with the Missouri Secretary of State Corporations Division. Forming an LLC or corporation does not automatically give you permission to operate at a specific address, collect sales tax, hire employees, or skip local licensing.

Missouri Department of Revenue tax registration

The Missouri Department of Revenue says a business must obtain a sales tax license by registering with the department if it makes sales of tangible personal property or taxable services. The department also says a business should register if it is a corporation responsible for corporate tax or if it has employees and must remit withholding tax.

Use the Missouri Department of Revenue business tax registration requirements and the Missouri online new business registration portal. The online registration portal is part of a combined effort by the Department of Revenue and the Department of Labor and Industrial Relations Division of Employment Security.

Employer registrations

If you hire employees, you may need Missouri withholding tax registration and unemployment-related registration. You may also need federal employer tax steps through the IRS. Do not rely only on a city or county license if you have employees.

Professional and occupational licenses

Some businesses need state professional licensing or board approval. Examples may include health care, real estate, accounting, architecture, engineering, certain construction trades, cosmetology, massage, private security, and other regulated fields. Start with the Missouri Division of Professional Registration and the board for your profession.

Zoning, home occupation, occupancy, building, fire, health, and industry permits

A business license or registration does not automatically make your location legal for your activity. Location-based approvals are often the step that delays an opening.

Zoning and home occupations

Zoning controls what uses are allowed at a property. A storefront, warehouse, office, commercial kitchen, home-based business, short-term rental, contractor yard, auto-related business, daycare, salon, or food operation may be treated differently.

For unincorporated St. Louis County, check the county Planning Department and zoning map. For a business inside a municipality, ask that municipality’s planning or zoning department. A home-based business should ask whether customers, employees, signs, parking, inventory, deliveries, noise, outdoor storage, or commercial vehicles are allowed.

Commercial occupancy

Commercial occupancy approval may be needed before you open a tenant space, take over an existing storefront, change business use, or move into a vacant building. In unincorporated areas or contracted municipalities, St. Louis County may handle the occupancy or code process. In other municipalities, the city may handle it directly.

Do not sign a lease without asking whether the space is already approved for your exact use. A space that worked for a clothing shop may not be approved for a restaurant, salon, daycare, auto repair shop, gym, warehouse, or production kitchen.

Building, electrical, plumbing, mechanical, signs, and land disturbance

Remodeling, installing equipment, changing plumbing, adding electrical circuits, changing HVAC, adding a grease interceptor, building walls, altering exits, installing signs, or disturbing land can trigger permits. Check St. Louis County Transportation and Public Works for unincorporated or county-enforced areas, and check the city building department if your address is inside a municipality.

Fire and life safety

Fire approvals can involve the municipality, St. Louis County, and/or a fire protection district. Restaurants, event spaces, childcare uses, assembly spaces, warehouses, auto uses, hazardous materials, and businesses with public occupancy should ask about fire inspections before opening.

Food, mobile food, temporary food, and catering

Restaurants, bars, bakeries, coffee shops, food trucks, caterers, commissaries, shared kitchens, temporary food booths, and some packaged-food businesses may need county health permits, plan review, inspections, and food code compliance. A city business license is not a food permit.

Food trucks and mobile vendors should also ask each city where they plan to operate about local mobile vending, parking, peddler, solicitor, special event, and fire rules.

Short-term rentals

Short-term rental rules can be local and may involve zoning, occupancy, fire, safety, tax, nuisance, parking, and neighborhood rules. Check the municipality if the property is inside a city, town, or village. For unincorporated areas, check county zoning, occupancy, and any applicable county or special district rules.

Contractors and trades

Contractors may face several layers: business licensing or registration, state professional licensing if applicable, county or municipal contractor registration, permits for each job, bonding or insurance documentation, and trade-specific approvals. Check the city where the contractor is based and the city or county where the work is performed.

What different business types should verify