Plumbing Contractor Permit Requirements in St. Louis, MO

Complete permit and license guide for starting a plumbing contractor in St. Louis, St. Louis City County, Missouri.

Updated 2026-03-14 5 stops $400–$1,200 est. 4–10 weeks to obtain all licenses
Get my personalized route — $14.99

Not legal advice. Requirements may change — always verify with your local government authority before applying. This guide was compiled from public and official sources (last updated ) and has not yet been independently source-verified — confirm each requirement before acting on it.

Federal — start here

1 stop
  1. EIN (Employer Identification Number)

    Required if you have employees or operate as an LLC or corporation. Free from the IRS.

    Official government source

    FreeImmediate (online application)

State of Missouri

1 stop
  1. Missouri Department of Revenue — Sales Tax License

    Required for all businesses selling taxable goods in Missouri. The state rate is 4.225%; local rates vary by city and county. Register online with the Missouri Department of Revenue.

    Official government source

    FreeImmediate (online application)

City of St. Louis / St. Louis City County

3 stops
  1. Missouri Plumbing Contractor License (local jurisdictions)

    Missouri plumbing licenses are issued at the local level. Kansas City and St. Louis both require Master Plumber licenses for business owners.

    Official government source

    Varies by city ($100–$300)2–6 weeks

  2. City of St. Louis License Collector — Business License

    St. Louis City is an independent city (not part of St. Louis County) and requires a Business License from the License Collector's office. This license must be renewed annually and displayed at your place of business.

    Official government source

    $50–$500/year depending on business type and gross revenues1–3 weeks

  3. St. Louis City County / St. Louis Plumbing Permit (per project)

    A separate permit must be pulled with the local building/plumbing department for each job. Inspections are required upon job completion.

    Official government source

    $50–$300 per project1–5 business days

Terminus

Open for business — est. $400–$1,200 · 4–10 weeks to obtain all licenses

Want this mapped to your exact business and structure, in filing order?

Get my personalized route — $14.99

Official Sources

Related Guides