How to become a plumbing contractor

Becoming a licensed plumbing contractor takes about five to seven years and runs through three stages: apprentice, journeyman, then master plumber or contractor. You log roughly 8,000 supervised hours as an apprentice, work a year or two as a journeyman, pass a trade exam plus a business-and-law exam, post a surety bond, and carry liability insurance. The exact hours, exams, and fees depend on your state, and a few states don't license plumbers statewide at all.

This guide walks the full path and then breaks down the rules in the states people ask about most: California, Florida, Illinois, North Carolina, and the City of Chicago.

The four steps to a plumbing contractor license

The license tiers are consistent across most states even when the hour requirements and exam names differ.

Apprentice. You register as an apprentice, usually through a union local (UA), a merit-shop program, or directly with the state. Apprenticeship lasts four to five years and combines paid on-the-job training with about 144 hours of classroom instruction per year. You learn pipe sizing, code, venting, backflow, and gas work under a licensed plumber.

Journeyman. After logging the required apprentice hours (commonly 8,000), you sit for the journeyman exam. A journeyman license lets you do plumbing work independently on the job but not run a business or pull permits in your own name. Journeyman pay nationally runs about $55,000 to $75,000 depending on the metro and whether you're union.

Master plumber. One to two years of journeyman experience qualifies you for the master exam, which covers advanced code, design, and supervision. A master can pull permits, sign off on inspections, and supervise journeymen and apprentices.

Plumbing contractor. This is the business license. It lets you bid jobs, hold contracts, employ a crew, and advertise as a plumbing company. The contractor license requires a named qualifying party (usually a master plumber), a surety bond, and proof of insurance. In many states the master plumber and the contractor's qualifying party are the same person.

What "licensed," "registered," and "certified" plumbing contractor mean

People search for licensed, registered, and certified plumbing contractors as if they're the same thing. They aren't, and the difference matters when you're verifying who's legal to hire.

Licensed means the contractor passed a state exam and meets experience and bonding requirements. This is the strongest credential and the one most states require to pull permits.

Registered usually means the contractor filed paperwork and paid a fee but did not necessarily pass a competency exam. Some states (and many cities) use registration as a lighter-weight requirement on top of, or instead of, a license. Florida, for example, has both Certified plumbers (statewide) and Registered plumbers (valid only in the local jurisdiction that issued them).

Certified is the term Florida uses for its statewide credential, but elsewhere it can refer to a trade certification (like backflow or medical-gas certification) rather than a contractor license. Always check what the issuing authority means by the word.

If you're hiring or building a list, the practical rule is: a license number you can verify against a state board beats any self-applied label. We cover how to check that in contractor license data by state.

How much it costs and how long it takes

The dollar cost of the licenses themselves is modest. The real investment is the years of apprentice and journeyman wages before you can charge contractor rates.

Item	Typical cost	Notes
Apprenticeship	Paid (you earn)	4-5 years, ~8,000 hours, starts around $18-25/hr
Journeyman exam	$50-$200	After apprentice hours are verified
Master exam	$100-$300	After 1-2 years as a journeyman
Contractor license + business filing	$100-$700	Plus LLC or corp registration in most states
Surety bond	$100-$600/yr	Bond amount set by the state; premium is a fraction of that
General liability insurance	$600-$2,000/yr	Higher for commercial and new-construction work
Continuing education	$50-$300/yr	Required to renew in most states

All in, the first license cycle costs roughly $1,500 to $5,000 in fees, bond, and insurance. Most people underestimate the timeline, not the money. The 8,000-hour apprentice requirement is the gate, and you can't test out of it by paying more.

Can a general contractor do plumbing?

This comes up constantly, and the answer depends on the state and the job.

In California, a B (General Building) contractor can include plumbing only when the project involves at least two unrelated trades. Plumbing as a standalone scope requires the C-36 Plumbing classification from the CSLB. So a GC remodeling a kitchen with framing, electrical, and plumbing can handle the plumbing under the B license, but a GC hired only to repipe a house cannot.

Most states draw a similar line. A general contractor can manage plumbing inside a larger build, but anyone performing or pulling permits for dedicated plumbing work needs a plumbing license held by the company or a licensed subcontractor. When in doubt, the permit office decides, and they almost always require a plumbing license number on the application.

What is a C-36 plumbing license?

C-36 is California's Plumbing Contractor classification, issued by the Contractors State License Board. It covers installing, repairing, and maintaining plumbing, water, gas, and drainage systems, including fixtures, water heaters, and backflow devices.

To qualify for a C-36 you need four years of journeyman-level plumbing experience within the prior ten years. You then pass two exams: the C-36 trade exam and the Law and Business exam that every California contractor takes. After passing, you post a $25,000 contractor bond and register your business entity. California had roughly 30,000 active C-36 licenses as of early 2026, making it one of the larger single-trade pools in the country.

State-by-state: California, Florida, Illinois, and North Carolina

Licensing is a state matter, so the same trade has different gates depending on where you work. Here's how the four most-searched states compare.

State	Issuing board	Contractor credential	Key requirement
California	CSLB	C-36 Plumbing Contractor	4 yrs journeyman experience + 2 exams + $25,000 bond
Florida	DBPR	Certified (statewide) or Registered (local) Plumber	4 yrs experience + state exam; Registered is jurisdiction-only
Illinois	IDPH + state contractor registration	Licensed Plumber + Plumbing Contractor registration	Apprenticeship + state plumber license, then register the business
North Carolina	NC State Board of Examiners (P-1/P-2)	P-1 (unlimited) or P-2 (restricted) Plumbing Contractor	2-4 yrs experience + exam; P-1 has no project-size limit

Florida splits its plumbers into Certified (CFC, valid statewide) and Registered (RP, valid only where issued). A CFC needs four years of experience and passes the state exam. If you only hold the local RP, you can't legally work outside the county that registered you.

Illinois licenses plumbers through the Illinois Department of Public Health, then requires a separate plumbing contractor registration for the business. North Carolina uses a P-1 (unlimited) and P-2 (restricted to projects under a dollar threshold) split, both issued by the State Board of Examiners of Plumbing, Heating, and Fire Sprinkler Contractors.

Licensing in Chicago and other home-rule cities

Big cities often layer their own rules on top of the state license. Chicago is the classic example. To work as a plumbing contractor in Chicago you need the Illinois state plumber license and a separate City of Chicago plumbing contractor registration. The city verifies the state credential, then issues its own.

New York City runs master plumber licensing entirely at the city level, with no statewide equivalent. Several Texas and Pennsylvania cities add municipal registration too. If you're targeting a metro, check the city building department in addition to the state board, because the city registration is what shows up on the permit.

Plumbing contractor salary and what the license is worth

Licensing is the difference between earning a wage and owning the margin. Journeyman plumbers nationally earn about $55,000 to $75,000. A master plumber running their own contractor business clears well past $100,000 in most metros, with the spread driven by commercial vs residential mix, service vs new-construction, and how many trucks they run.

The contractor license is what lets you bill the job rather than the hour. It's also what lets you bid municipal and commercial work, which usually requires a licensed-and-bonded company on the contract.

Why this matters if you sell to plumbing contractors

Most visitors to this page want to get licensed. Some are on the other side: software vendors, suppliers, financing companies, and manufacturers who want to reach licensed plumbing contractors as customers. The license data that gates the trade is the same data that makes a clean prospect list.

Every state board that licenses plumbers publishes a registry. Those registries carry the business name, license number, classification (C-36, CFC, P-1), status, and often the responsible party. TradeBridge builds contractor lists from those authoritative sources, segmented by trade and verified against the issuing board. See plumbing contractor data for what a plumbing list includes, or license verification if you already have a list and need every record checked against the state board.