Plumber licensing in Missouri
Licensed locally, not statewide
Missouri has no statewide license for this trade. The city or county decides — check the jurisdiction the job is actually in before you travel.
✓ Verified 10 August 2026 · mixed
Starting as an apprentice
Missouri registers apprentices locally, not statewide
- What it is called
- Apprentice application, where the jurisdiction runs one
- Who issues it
- the city or county - St. Louis city's Board of Examiners approves apprentice applications
No state credential. St. Louis city approves apprentice applications at its monthly board meeting; St. Louis County instead documents apprentice time on an employer-signed Affidavit of Employment Experience. Fees and mechanics vary - ask the jurisdiction.
Bringing your license from another state
Missouri has no statewide plumber license — licensing here is a city and county matter, so the question is never "does my license transfer to Missouri" but "what does the city where the job sits require." Some local authorities honor out-of-state or neighboring-city cards; many run their own exams.
Can you work while it is pending?
There is nothing to wait for at state level. Whether you can start depends entirely on the local jurisdiction's rules — call the city or county building department where the job sits and ask about their plumber licensing, permits, and any card they require.
The exam and the hours
No state exam exists. Cities that license plumbers run their own examinations on their own calendars — the local building department is the source of truth.
How apprenticing works here
No state apprentice system exists; local jurisdictions that license plumbers set their own helper and apprentice rules, and registered apprenticeships run through US DOL sponsors.
The local picture
The local layer IS the licensing system here. Verify the specific city's requirements before every placement; two jobs an hour apart can sit under different rules.
If you want to contract for yourself
Contractor and business requirements likewise vary by jurisdiction; the employer's local registrations are the employer's problem, but confirm they exist before the crew rolls.
Checked against the state board or statute. Rules change — confirm with the board before you travel or accept work. This is information, not legal advice.
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