Complete guide to permits and licenses required to start a plumber in St Louis, MO. Fees, renewal cycles, and agency contacts.
Not full license but required for contractors.
Required for all LLC formation in Missouri. Annual report also required ($20 online fee).
All active Missouri LLCs must file annually regardless of industry.
Required for any business entity engaging in plumbing work. Must designate a licensed supervising plumber.
LLC must employ/partner with at least one licensed Supervising Plumber. Prerequisites: 5 years experience or approved education + pass exam.
Required for employees performing plumbing work under supervising plumber.
File with county clerk where principal place of business is located, then with Secretary of State.
Most plumber businesses need this if charging sales tax on materials.
Plumbers may be required to collect sales tax on materials and fixtures sold to customers. Labor for repairs is generally not taxable unless combined with taxable materials. Registration is required within 15 days of starting business. Source: https://dor.mo.gov/forms/publications/salesuse-tax-instructions/
Verify zoning district allows commercial plumbing business.
Home occupation permit available for residential zoning.
Comply with sign code Chapter 18.
Required for all employers paying wages to employees in Missouri. Must file Form MO-264200. Registration can be completed via the Missouri Business Portal. Source: https://dor.mo.gov/forms/publications/withholding-tax-instructions/
Employers must register using Form DES 2040. Tax rate varies by experience rating (0.25% to 6.25% in 2024). Applies to first $11,000 of each employee's annual wages. Source: https://ded.mo.gov/employment-security/employer-tax-information/
Default LLCs are pass-through entities and do not pay corporate income tax. If the LLC elects corporate taxation (Form 8832), it must file Form MO-8871. Missouri corporate income tax rate is 4% on net income. Source: https://dor.mo.gov/forms/publications/corporate-income-tax-instructions/
All Missouri LLCs must file an annual report. While there is no franchise tax for LLCs (unlike corporations), the report is mandatory. No tax payment required. Source: https://www.sos.mo.gov/business-entities/annual-report
Many Missouri cities (e.g., Kansas City, St. Louis, Springfield) require a local business license or pay a privilege tax. For example, Kansas City requires a Business Tax Registration ($50/year). Source: https://www.kcmo.gov/178/Business-Tax-Registration
Requires passing exam and proof of insurance. Specific to plumbing trade.
Required for all businesses; plumbing LLC must specify trade.
Merchant/seizure license for businesses with inventory or sales.
Requires 4 years experience or journeyman license + exam.
All businesses must obtain; separate from contractor license.
Required for offices/stores over certain size.
False alarm ordinance strictly enforced.
Missouri law (Mo. Rev. Stat. § 287.030) requires any employer with at least one employee to maintain workers’ comp insurance. The employer may also elect to be self‑insured if they meet statutory financial‑ability criteria.
Missouri does not require general liability insurance for plumbing businesses, but many municipalities and commercial contracts require proof of coverage.
While not required by Missouri law, professional liability insurance is often recommended for contractors who provide design or consulting services.
Missouri law (Mo. Rev. Stat. § 332.020) requires a $10,000 surety bond for a full‑scope plumbing contractor license; a $5,000 bond is permitted for a limited‑scope license.
Missouri statutes (Mo. Rev. Stat. § 303.030) require minimum liability coverage of $25,000 per person, $50,000 per accident, and $25,000 for property damage for any vehicle on public roads.
While not mandated, product liability coverage is advisable for contractors who retail plumbing supplies.
Plumbing businesses do not sell alcoholic beverages; therefore liquor liability insurance is not applicable.
The EIN is required for all LLCs that have employees or that elect corporate tax treatment. Single‑member LLCs with no employees may use the owner's SSN for tax filing, but obtaining an EIN is recommended.
LLCs are pass‑through entities by default. Estimated quarterly tax payments are required if the LLC expects to owe $1,000 or more in tax for the year.
Employers must also maintain OSHA 300 Log injury records if they have 10+ employees and are not exempt.
Exemptions apply to low‑hazard industries; plumbing is generally considered high‑hazard, so exemption unlikely.
Requires nondiscriminatory service practices and reasonable accommodations for employees with disabilities.
Certification is required for each individual who performs the work, not the business entity.
Only applicable if the business handles refrigerants; otherwise not required.
Plumbers must avoid deceptive claims (e.g., “guaranteed no leaks”) and must disclose any material connections in endorsements.
Requires payment of at least federal minimum wage, overtime for >40 hrs/week, and recordkeeping of hours worked.
Employers must retain I‑9 forms for 3 years after hire or 1 year after termination, whichever is later.
Most typical plumbing services do not involve DOT‑regulated hazardous material transport; this requirement applies only in those specific cases.
Electronic filing required if 250+ forms are issued.
Forms must also be filed with the Social Security Administration (SSA) by the same deadline.
The FTC Home Improvement Rule requires clear and upfront disclosures to consumers regarding project costs, timelines, and cancellation rights; it applies to plumbing work exceeding $2500 in St. Louis.
No, there are currently no industry-specific federal licenses required for plumbers; however, you must still comply with all relevant federal regulations regarding business operations and taxes.
The FTC can impose substantial financial penalties for deceptive or misleading advertising practices, and may also require corrective advertising or other remedies.
If your LLC is taxed as a disregarded entity or partnership, you’ll typically file annually with the IRS, often using Form 1065; the specific form and schedule depend on your business structure.
The IRS requires you to keep records documenting your income, expenses, and other financial transactions for at least three years, and potentially longer depending on the specific record type.
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