Skip to main content
CityRuleLookup

Jefferson County, MO Building Safety: Plumbing Permits (2026)

Some Restrictions
Compiled from the official code textEditor Martyn O'NeillLast verified August 2026

Key Facts

Governing code
IPC 2015 + local amendments, Art. VIII
License term
3 years, Section 500.070
Permit fee
$125 residential / $160 commercial
Sewer connection
Required within 400 ft of public sewer
Max penalty
$1,000 fine or 1 year jail

Summary

Jefferson County requires a county Plumbing License before any contractor installs, alters or repairs plumbing fixtures, piping or drainage connected to a water or sewage system, plus a building permit before work begins. Section 500.070 sets a three-year license term for applicants who pass a master plumber exam, and the county has adopted the 2015 International Plumbing Code with local amendments under Article VIII, Section 500.450.

These county ordinances apply to unincorporated areas of Jefferson County. Incorporated cities within the county may have their own rules that take precedence over county-level regulations.

Authority. The Code Official shall be and is hereby authorized to grant a license to any person, firm or corporation (hereinafter "contractor") found to be qualified to engage in the work of installing or altering any plumbing fixtures, appurtenances, apparatus, equipment or components thereof used in the installation of a plumbing system within or adjacent to any structure. The license shall be issued in the name of the contractor and a responsible person shall be listed on the license. The license shall be valid for a period of three (3) years. ... No contractor shall perform plumbing work or hold itself out in any advertising medium or publication as being available to perform plumbing work unless licensed pursuant to this Section.

Full Breakdown

070 authorizes the Code Official to license plumbing contractors for a three-year term. An applicant must show that at least one employee is at least twenty-one years old and has passed a master plumber exam scoring seventy percent (70%) or better within the past six years, plus either a mechanical trade-school diploma and four years of practical plumbing experience, six years of hands-on installing, altering or repairing piping and water-supply systems, or a two-year trade or technical college diploma with four years of practical experience.

C bars anyone from performing or advertising plumbing work without the license. 7. 190 if they occupy the home, personally perform all the work, keep only one permit open at a time, and pass a written homeowner exam scored at least seventy-five percent (75%); the homeowner permit runs for one year. 00 inspection or re-inspection fee.

Violations & Fines

Beginning plumbing work before the permit issues costs the contractor an extra penalty equal to one hundred percent (100%) of the usual permit fee, on top of the fee itself, under Section 500.300.C, and the Code Official can disconnect utility service. Anyone who violates the Building Code, including plumbing work done without or contrary to a permit, commits a misdemeanor under Section 500.300.E punishable by a fine up to $1,000.00, up to one year in jail, or both, with each day of continued violation counted as a separate offense.

Frequently Asked Questions

Does Jefferson County require a permit for plumbing work?
Yes. Section 500.010 adopts the International Plumbing Code 2015 with county amendments in Article VIII, and Section 500.070 bars any contractor from installing or altering plumbing fixtures or piping without a county Plumbing License, issued for a three-year term to applicants who pass a master plumber exam. Starting work before the permit issues adds a 100% fee surcharge under Section 500.300.C.
Can a homeowner do their own plumbing work in Jefferson County?
Yes, under Section 500.190, if it is a detached single-family home the owner occupies, the owner personally performs all the work, only one permit stays open at a time, and the owner passes a written homeowner exam scored at least 75%. The permit is valid for one year and does not waive any material, design or fee requirement of the Building Code.
How far must a building connect to the public sewer in Jefferson County?
Amended Section 701.2 of the International Plumbing Code requires any building with plumbing fixtures and drainage piping to connect to a public sewer if the structure sits within four hundred (400) feet of that sewer's property line, unless it qualifies for an exception under the county's On-Site Sewage Treatment Code.

Sources & Official References

Other rules in Jefferson County

All Jefferson County rules

Compare Jefferson County to another location·View the Missouri building safety overview

Get notified when Plumbing Permits in Jefferson County, MO changes

We'll email you the moment we detect a change in the code. No spam, unsubscribe anytime.

We'll never sell or share your email. One-click unsubscribe in every email.

See something wrong?

Help us keep this page accurate. If you notice an error or outdated information, let us know.