Louisville Plumber License and Permit Requirements

Louisville's Two-Layer Licensing System

Working as a plumber in Louisville means navigating two separate authorities. Your trade license — journeyman or master — comes from the state DHBC. But Louisville Metro's Department of Codes and Regulations requires a separate local contractor registration before you can pull permits or perform work within Jefferson County.

This dual structure trips up experienced plumbers who assume their state master license is enough. It is not. Louisville requires local registration, local insurance verification, and local fee payment on top of the state credential.

Type A vs Type B Contractor License

Louisville Metro offers two contractor license tiers:

Type A License — $125/year Allows you to hold multiple active permits simultaneously. This is the standard choice for plumbing contractors running more than one job at a time. You need proof of $250,000 commercial general liability insurance and current workers' compensation coverage.

Type B License — $50/year Limits you to a single active permit at any time. Designed for smaller operations or plumbers who handle one project before starting another. Same insurance requirements apply.

Both types require that you hold a valid Kentucky master plumber license. Journeymen cannot register for either tier — they work under a registered master's umbrella.

The Permit Workflow

Here is where Louisville diverges from most Kentucky cities. Plumbing permits in Kentucky are state-issued, not local. But the workflow in Louisville involves local review steps before the state permit is released:

1. Register locally with Louisville Metro Codes and Regulations (Type A or B).
2. Submit plumbing and riser diagrams to Louisville Metro Public Health and Wellness (LMPHW) for plan review.
3. Submit grease trap/interceptor plans (if applicable) to the Louisville Metropolitan Sewer District (MSD) under their FOG Management Policy.
4. Obtain state plumbing permits through the DHBC website once local health and sewer approvals are complete.
5. Schedule state inspections — rough-in, underground, and final inspections are conducted by Kentucky state plumbing inspectors, not Louisville Metro staff.

Gas permits follow the same state-level path. Louisville's online permitting portal handles structural and building permits, but it explicitly routes plumbing and gas work to the DHBC.

Insurance and Tax Requirements

Beyond the state's $250,000 general liability minimum, Louisville Metro requires proof of workers' compensation insurance at registration. You also need a Jefferson County occupational tax account — Louisville levies an occupational license tax on net profits and employee wages that applies to plumbing contractors operating within the county.

Common Mistakes

The most frequent error is assuming that a state master plumber license lets you start pulling permits in Louisville immediately. Without the local contractor registration, your state permit applications for Louisville addresses will be flagged. The second common mistake is submitting plumbing plans directly to the state without routing through LMPHW first — for commercial or food-service projects, the state won't issue permits without local health approval on file.

The Kentucky Plumber License Guide covers the full Louisville Metro registration process alongside the state licensing pathway, including the specific forms and insurance certificates you need at each step.

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